Bottlehead Forum

Bottlehead Kits => Legacy Kit Products => Topic started by: porcupunctis on October 21, 2011, 01:03:03 PM

Title: Pending Paramour Build
Post by: porcupunctis on October 21, 2011, 01:03:03 PM
I recently was able to purchase a set of Paramours with the c4s upgrade that have never been assembled.  According to the documentation, it was packed by Eileen herself and dated 2002.

I have the bases already made and plan to send the plates off for anodizing.  I won't have an opportunity to do any soldering for a while.  Maybe not until my holiday break at the end of December.

So, I thought I'd ask the most knowledgeable folks I know: "What would you do?"

I've given Wardsweb a good look and I'm a little confused about the resister change in the c4s that he suggests.

I want to build them as a mirrored set.  Any thoughts on whether that is a good or bad idea would be helpful. 

I've checked out the Magnequest Iron and would like some good opinions on the value there.  A set of full nickel iron would cost more than I have invested so far but would still be less than Paramounts without the upgraded iron.

Any other "best build" ideas would be much appreciated.  I have the luxury of time and I'm in no hurry to start until I know just what I want to do.

Grainger, thanks for the suggestion.  I was thinking the crackle thread was getting off topic myself.

Title: Re: Pending Paramour Build
Post by: Paul Joppa on October 21, 2011, 02:27:45 PM
From the date, those are original Paramours, not the Paramour II. You probably have the Hammond power transformers - there's a label stuck to the core. You have the 6" by 10" chassis, so there is less room for messing around than the Paramour II which uses the Paramount chassis, 8" by 10".

You probably have the white plastic in-line fuse holder. Those things are pretty flimsy and a pain in the backside; I'd look for something better.

At the time of that kit, we had to use ordinary red LEDs; it was a few years later that we finally found the right ones which we now ship with all C4S applications. Your LEDs have a slightly higher voltage drop, so the current set resistor should be a bit higher than the original. The original was two 499-ohm resistors in parallel; the corrected value is one 499 and one 750 in parallel. The change is not always necessary, it depends on the particular 12AT7.

If you have the magnet wire for use as the ground buss, I'd say go get some tinned buss wire to replace it. The magnet wire is special and very good sounding but it's an absolute pain to solder - the coating is tough and super high temperature; most people get bad solder joints with it the first time (and often the second and third times!)


As others have said, mirrored pairs are very confusing. They may have more problems, but it's hellish to troubleshoot those problems!

The iron upgrade is quite valuable, but you may want to build them stock first - it's not a bad little amp in stock form, and much easier to build when you can follow the manual. I can't find the old upgrade transformer instructions - hopefully they are still around. There were never any instructions for building the upgraded amp directly.
Title: Re: Pending Paramour Build
Post by: Grainger49 on October 21, 2011, 02:36:09 PM
Brought over from the other thread:

Quick answers:

If you are dyslexic don't try it.  Seriously it is tricky, build the stock Paramour first then go over the tube pin connections 4 times as you build the mirrored Paramour.  Number the tube sockets and terminal strips so you will always see the numbers.  Triple check as you build the second.

Yes Magnequest is well worth the cost!  And buying all nickel output transformers is even better.

I would figure that the C4S resistor is the "R1" resistor which is the current setting resistor.  PB has advised that thick film is good in this position.

I changed the driver tube to a 76 (requires a larger hold in the plate, I used a hole punch, and a different cathode resistor).  It is an ST shaped tube and looks good next to the 2A3.  I think it sounds better.  I can send you the instructions.  I also widened a few terminal strip holes with my Dremel on the second Paramour.  I can flip mine over and find which ones are a tight squeeze for the stock build.  As you might imagine no capacitor in my Paramours is stock.  There are KK Teflons you can put between the two stages.  With upgraded iron PJ will tell you what capacitor to use but it isn't the stock value so a new cap here.  Power supply caps upgrade well and the power supply resistor is replaced with the stock plate choke when you get the Magnequest.  There is probably still an active link for the iron upgrade instructions.

More later, less sooner.
Title: Re: Pending Paramour Build
Post by: Grainger49 on October 21, 2011, 02:42:28 PM
Some additional information:

PJ is right about it being crowded.  Here is a link to a picture of my over modified Paramours:

http://www.bottlehead.com/smf/index.php/topic,1185.0.html

If you upgrade the iron you will need standoffs to put the old plate choke above terminal strips 1-5 and 6-10 (I think I got the numbers right).  Here is the link for the upgrade iron instructions:

http://www.bottlehead.com/et/adobespc/Paramour/paramourupgrade/paramourironupgradekit.htm

You can mount the hum balance pot so it can be adjusted from the top, a handy thing to do.  Drill a hole in the top plate between the driver tube and the output tube and to the rear of the input RCA jack.  You will need to reroute the ground wire in this area.

Still more later about crowded terminal numbers.  I need to check my manual.
Title: Re: Pending Paramour Build
Post by: porcupunctis on October 21, 2011, 03:56:33 PM
Wow, I'm not going to remember all the questions generated so far but time is on my side.

Grainger, if I go the 76 route on the driver, what is the best way to enlarge the hole.  There are a lot of things in my garage but I don't have a hole punch that size.

It seem that between the two, you have convinced me that the Magnequest upgrade is worth doing.  Sounds like I need to dig around the attic and find some things to sell on eBay.

I have a pretty good understanding of how tricky the "mirror" thing will be.  I have to teach high school kids how to do reflections about the X and Y axis and I know it can be more than a little deviling.  I understand that I will have to be patient, meticulous, and careful.  I'm afraid that the challenge is what I like about this idea.  I'm also just a tad bit OC so I tend to like symmetry.  That's another story.

This build will not go quick.  It will be weeks if not months before I have any time to devote to this project.  I also have a Seduction and a Crack (with upgrades) to work on as well.  My priority will be the Paramours.  There is just something that I find elegant about the monoblock 2A3s. 

Thank you both for all the advice so far.  As progress is made, I will post here.  As I write this the finish is curing on the bases.  I will try to get some pics.  A start.
Title: Re: Pending Paramour Build
Post by: Grainger49 on October 21, 2011, 04:34:24 PM
Randall,

I have the hole punch needed.  I can lend it to you.  I should mention that the 76 driver doesn't have as much gain as the stock tube.  In most Bottlehead systems that isn't a problem.  It is less than a quarter of the volume control turn on my FP 2.
Title: Re: Pending Paramour Build
Post by: 2wo on October 21, 2011, 05:43:28 PM
Build it stock,

 If you have a question, or something goes wrong, we can help.   It's fun to go in and upgrade or just change. Just don't try to do it all at once.
  If you start out, mirror image, swapping out the first stage, changing the iron and just about everything else. If you need help, you'll need to ask the designer. And that my friend would be you :).

I don't want to discourage, DIY or trying new things but build it. Get it going, maybe even listen to it...John     
Title: Re: Pending Paramour Build
Post by: porcupunctis on October 21, 2011, 05:47:47 PM
Grainger, I may take you up on the hole punch but I think I will want to get the "mostly stock" build together and tested (resistance and voltage checks) before doing too much on the exotic side.

I did a search for the 76 tubes and found a few nice NOS ones.  The looks will certainly match the 2a3 very well but is there a sonic reason that you went with the 2a3s?  I don't think the loss in gain will be a problem for my setup.  I'm currently using a SEX amp to power my speakers and I have plenty of room on the volume of my FPIII.  I'm thinking that the Paramours even with the 76's will have more power than the SEX.  At least as much.

thanks again,


Title: Re: Pending Paramour Build
Post by: porcupunctis on October 21, 2011, 05:56:20 PM
John, good advice and I will definitely take it.  Especially with the mirror build I will start pretty much stock and then add upgrades one at a time.  Right now I'm just trying to make a "wish list" based on good first-hand knowledge.

I'm one of those that will mull ideas over in my mind for weeks on end and then think on them a bit more before getting too crazy with the soldering iron. 

Thanks again.  The bottlehead gear is great but it's the community here that makes them awesome.
Title: Re: Pending Paramour Build
Post by: Paul Joppa on October 21, 2011, 09:42:45 PM
A note on upgrade iron:

The original upgrade plate choke was the BCP-15, 40 henries at 50mA. For the Paramour II, Mike modified that design with some improvements in construction and materials, but the same specs - it's called the BH-5.

For output transformers there are three candidates:

1) Originally we had one made for us by Edcor. It has a 4K primary with 4. 8, and 16 ohm taps on the secondary. They have not been made for at least 5 years, so it might not be possible to find a pair. They have to be installed on a slight diagonal to fit right.

2) The chassis plate was used for the Afterglow and derivatives, and is drilled for a TFA-2004. They are $700 a pair in nickel now, if you can talk Mike into making some - total overkill but it's my dream transformer for a 2A3. Primary is 3K which is lower than the design value, but the high inductance choke makes up for that. Secondary is 4, 8, and 16 ohms.

3) For the Paramour II and Paramount, Mike came up with a special Bottlehead construction for the TFA-2004Jr (the Junior design has a smaller lamination stack and is in a channel frame; it's not in his standard catalog at this time). The Bottlehead version is called the BH-6 and is part of the Paramour II upgrade package. It has slightly better treble (if such a thing is possible) but less power handling than the TFA-2004. Still, it can take the 8 watts of a 300B, so it's loafing with a 2A3. The chassis plate is, by a fortuitous accident, drilled for this size transformer. Unfortunately it has exposed solder terminals which must be carefully insulated for safety. Same primary impedance as the TFA-2004 but only 8 and 16 ohm secondary taps.

I have not mentioned the Stereomour iron, because no decision has been made about selling it separately.
Title: Some Answers
Post by: Grainger49 on October 22, 2011, 03:24:05 AM
I'm thinking that you are asking why I went for the 76 over the stock tube.  Yes, the 76 changes the sound as well, but really looks cool too.  I have a local friend, poster chocadude, who brought over his upgrade iron and 76 driver Paramours.  We compared them with my stock Paramours.  I knew I wanted that sound immediately.  I did the 76 driver first and liked the improvements.  Then the iron (BCP-15 and TFA-2002 {no nickel}) was a year later.  There is no doubt that was a worthwhile improvement as well.

The 76 doesn't affect the output, it stays at 3.5W.  So you will get more power than the SEX but will need to use more of the FP III volume control to get to maximum output.

  .  .  .   I did a search for the 76 tubes and found a few nice NOS ones.  The looks will certainly match the 2a3 very well but is there a sonic reason that you went with the 2a3s?   .  .  .   I'm thinking that the Paramours even with the 76's will have more power than the SEX.  At least as much.

thanks again,



Title: Re: Pending Paramour Build
Post by: elcraigo on October 23, 2011, 03:07:28 AM
Randall,
If you like, contact me off line. I might be able to help with some upgrade parts.
I've built (2) sets of Paramour I and (1) set of Paramour II.
As with Grainger, I like the 76 tube.
Now would be the time to make the hole larger, just get a set of the hole shrinkers to use the 12AT7.
Look in the parts section of the Bottlehead store.
Title: More Suggestions - PM If You Need The Hole Punch (knockout)
Post by: Grainger49 on October 23, 2011, 08:17:48 AM
Give me a shout if you need the hole punch.  I will be out of town from mid day Tuesday till some time Friday.

Looking at the Paramour build picture I remembered that I wired the output transformer directly to the output banana plugs, not to a terminal strip first.  Twist the wires and go directly to the plugs.

Also looking at that picture, it is obvious that the hum balance pot will fit well between the input RCA jack and the transformer.  In the standard instructions it is soldered to the tube socket (what a PITA!).  Bottlehead no longer does this in any of their products today.  Just put the hole in a spot nearer the 16-20 terminal strip and near the front.  The heaters are AC, so keep it away from the input by an inch, maybe put the terminals toward the rear of the chassis.  Yes, this is also something to do from the start since it is easiest if done before the chrome process.

If you have a newer Paramour (1) manual there will be a pink sheet of corrections.  If not I can scan that and send it to you.  I went through my manual and put "see addendum" at each step that was changed.

Title: Re: Pending Paramour Build
Post by: porcupunctis on October 23, 2011, 11:43:12 AM
The kit is definitely Version I and not II.  I do have the pink sheet with manual corrections.  It has the Hammond power transformer.  Output TFs are SPECO T7010s.

Grainger, that is one crowded box.  It should still be in the gallery though.  Everyone will be amazed at how you got everything in there.

It looks like I will have a few chassis mods to make ahead of time.

1.  Definitely drilling a hole for the hum pot.  For safety more than anything.  I can only imagine how easy it would be to zap myself into next Tuesday trying to adjust that thing with the power on.
2.  Enlarging the driver hole in advance does seem to make sense.
3.  I would also like to sneak in a chassis mount fuse holder.  On that note, an IEC connector with the build in fuse holder would be even better but now I would need to stretch this out a few inches to do that.

I'm beginning to think that a good option might be to design a nice 8X10 plate with FP express.  I could get everything on my wish list and end up with some room to work around in.  Of course, I would also have to make new bases but the woodwork would be no problem and I could use the two bases I made for this project for my pending Seduction and Crack builds.

I have no idea what two custom panels will run so that may not be an option.

This is quickly turning from a kit build to a scratch build but I pretty much crossed that line with the mirror build idea.

On the subject of mirror build:  The problem I see with this kind of assembly is that everything can be reflected except the tubes themselves.  Too bad they never made left and right handed tubes with reversed pin-outs.  Then you could make a mirror build as a perfect reflection of one another. 

My head is just swimming with all kinds of ideas and tips.  I'm going to have to walk back through this thread and make a list of things to buy, things to remember during the build and things to consider.  I knew I'd get lots of good advice and I sure did.  I'll need to let all of this soak in bit.  Then I can commit to a plan and start executing.



Title: Re: Pending Paramour Build
Post by: Paul Joppa on October 23, 2011, 02:05:07 PM
A pair of FPE panels will run you about $100.

Personally, I am very familiar with the stage of a project where you keep adding one more tiny improvement until it bears no resemblance to the original idea and has become so complex you just put the parts in the basement and start another project ... I have six pair of amplifiers in my work area, in various stages of completion!  :^)  My advice is to resist that temptation and build the thing as close to stock as you can. That way, the manual will be of more use to you, the community here will be more able to help with problems should they crop up, and you stand a much better chance of actually listening to the thing.

A fuse holder like this would fit without fancy drilling - you could even glue it down with hi-temp silicone RTV:

http://www.mouser.com/ProductDetail/Schurter/00316001/?qs=sGAEpiMZZMukmSYeDOiaDEbl%2fHtQh2iy4ZR8b739kXI%3d
Title: Re: Pending Paramour Build
Post by: 2wo on October 23, 2011, 03:03:37 PM
You can mount an IEC connector in the back of the wood base. attache the wires with spade connectors or make them long enough so you can lift the top off...John
Title: Re: Pending Paramour Build
Post by: Grainger49 on October 24, 2011, 03:08:10 AM
I'm with John, I have always thought the IEC would be best mounted in the rear of the base with stranded, pull from SO cord, connection long enough to allow you to flip the top for troubleshooting.

The square hole in wood is harder than it is in sheet metal.
Title: Re: Pending Paramour Build
Post by: ssssly on October 24, 2011, 03:33:08 AM
Can also modify the top plate for an IEC. Just drill out the corners of the square you want to cut and use dremel or small blade. Then you can use a file to fine tune. Most IEC receptacles have an overhang so you don't have to be medically precise to have it still look good.

Voltseconds web site has a treasure trove of Paramour stuff. I would strongly recommend giving it a read if you haven't already.
Title: Re: Pending Paramour Build
Post by: porcupunctis on October 24, 2011, 08:32:56 AM
I think Paul described my mental state very well.  When I did software programming we called this "feature creep"  where we kept coming up with great ideas until we had designed something that could never be built.

So, I'm going to focus on building a really nice set of Paramour I's.  After all, this may be the last Paramour I kit left unassembled in the world. 

So my plan for now is this: 
1.  Use the Paramour bases that I have made.  I just ordered badges to make them look official. 
2.  I'm going to build (initially) a very close to stock kit.  This will make it easier to follow the manual and especially help with the mirror build.
3.  Still planning a mirror build.
4.  Instead of sending the plates off for anodizing, I'm going to polish one side of each.  I'm already about half-way there.
5.  I do plan on drilling a hole to mount the hum pot. 
6.  I will take Paul's advice on the magnet wire and use something that is easier to solder.
7.  I will find a place to glue or otherwise mount a fuse holder like Paul suggested.  The inline has to go. 
8.  I think I may also punch the driver hole out to accomodate the octal socket for future upgrades. 
Only because it will be a real hassle to try to do it later.  I've already ordered the hole shrinkers.

The following, I think I will defer for now:
1.  Iron upgrades.
2.  IEC mounting.

This will make a project that is true to the Paramour I design and still allow for some future enhancements.



Title: Re: Pending Paramour Build
Post by: porcupunctis on October 24, 2011, 08:34:44 AM
Grainger, tell me how the hole punch works.  How badly can I mess up my plates if I get this wrong?
Title: Re: Pending Paramour Build
Post by: howardnair on October 24, 2011, 01:33:42 PM
the mirror idea sounds real fun--here is iec with fuse-they can be found cheaper elsewhere --i used these in my stereomour builds--
http://www.revolutionpower.com/p/Furutech+FI-03+Gold+IEC+Inlet+wFuse+Holder/295/

howie
Title: Re: Pending Paramour Build
Post by: Grainger49 on October 24, 2011, 01:37:53 PM
The hole punch is mechanical.  Look at this link:

http://www.harborfreight.com/knockout-punch-kit-91201.html

There are two circular hardened steel pieces that fit one inside the other.  You will already have a hole for the driver.  Place the smaller one on top and the larger one below the plate.  Insert the supplied screw and tighten till it just gets tension on the two.

The hole is going to be the outer size of the smaller, the inner size of the larger.  Position the knockout exactly and start turning the hex head with a ratchet wrench.  The top will bend a little but it can be straightened easily.

It is easy to tell when it is through. 
Title: Re: Pending Paramour Build
Post by: porcupunctis on October 28, 2011, 10:08:57 AM
Status report;

I've secured a hole punch locally.  I live in one of those neighborhoods where everyone has some kind of shop in their garage.  Woodworking, metalworking, glassworking, you name it and someone on my block has the tools. 

Grainger, thanks for the offer on the hole punch. but I have a question.  How do I orient the holes for the socket hold-down.  Should I drill them parallel to the long side (like the 2A3 socket) or parallel to the short side (like the original)? 

My goal is to do the assembly and build over the long Thanksgiving weekend.  I have a lot of work to do on the chassis plates but I think this is a manageable goal. 

The Volley ball team at the HS I teach at is going into sectional play (at home) for a chance to go to state finals.  They are 32-0 and a lot of them are in my Algebra II and College Algebra class.  I also coach Cross-Country and our Districts are the same weekend.  I'm thinking that this won't be the most productive weekend but it will sure be fun to see these kids compete. 

On another note:  I sent my Crack and Seduction plate off to be anodized today so that will be another topic in the near future.
Title: Re: Pending Paramour Build
Post by: porcupunctis on November 01, 2011, 03:04:24 PM
The following progress has been made:

1.  The driver tube socket hole has been enlarged to accomodate a future 76 update.  The hole-shrinkers have been ordered and I expect them any day.
2.  Holes have been drilled for the hum pot and a fuse holder.
3.  Chassis plates have been polished to an almost mirror finish on mirror sides.
4.  Wood bases are ready to go.

I have been given the gift of time.  Our girls VB team won their sectional tournament and are off to compete at State this weekend.  As a consequence, school will be letting out on Thursday at noon and we'll have Friday off as well.  I haven't had a chance to do anything cosmetic with the iron but I think I might go ahead and do the build while I have some days off.  The output transformers will probably get upgraded anyway and I can do the cosmetics then.  Maybe by then I will have figured out what I want to do with them, anyway.

More later,

Title: Re: Pending Paramour Build
Post by: porcupunctis on November 01, 2011, 04:06:49 PM
Grainger, just ordered a set of Obligatto caps for the Paramours.  2 - 0.1 mfd and 2 - 3.3 mdf.

I just have to try them out after you've spoken so highly of them.  These will probably go in after the initial build so they will represent the very first "upgrade".
Title: Re: Pending Paramour Build
Post by: vladimirwolfe on November 01, 2011, 06:54:05 PM
Hey Randall,

I just wanted to let you know that there's a least one other "virgin" Paramour I out there and it's in my closet. I even have the iron upgrade. Hoping to build it this winter if the skiing isn't any good ;-)

Good luck on your build!

Doug
Title: Audio Chepaskate
Post by: Grainger49 on November 02, 2011, 12:57:13 AM
Randall,

October is over so the Halloween avatar is retired for another 11 months.  Under my present avatar is my mantra.  I DO appreciate the high priced spread, Mundorf Silver/Oil, caps in my Foreplay but I get a kick from bang-for-the-buck finds like the black Obbligato and KK Teflon caps.  I wasn't the source for either of these on the BH forum originally but I'm a supporter.

In my past experience only one Bottlehead hasn't liked the black Obbligato caps.  But we all have different tastes.  I found them smooth and clean.  The bass is good, I'm finding out how good now with the Eros.  I admit it was a point of running out of funds when I bought upgrade iron that drove me to the Obbligatos.  I needed a 10uF parafeed cap and they were suggested.  At the time they were $8 each so it was an easy decision.
Title: Re: Pending Paramour Build
Post by: porcupunctis on November 02, 2011, 04:25:34 PM
I ended up with the "Gold Premium" Obbligatos.  I didn't see the "black" variety.  Just checked again.  They were still a good price compared with others that I checked out.

Those caps can sure add a lot to the price of your kit.  I was pricing come big caps for my eventual Crack build and "Hoo Doggie!" those babies are expensive.  Dock wasn't kidding when he said you can double the price of the kit by upgrading the caps (or something like that).

I worked on the Paramours tonight.  I was able to get all the hardware assembled except the driver tube socket.  I'm still waiting on the hole shrinkers and I just found out that they shipped today.  This means that I will not be able to complete the build until next weekend.  That's OK, I have other projects to work on.

Grainger, where can I get a good set of 76 tubes?  Do I need a matched set?  I did order the 5 pin tube socket so it will be here.  I don't plan on converting to the 76s right away but want to have everything on hand when I do.

Doug, that's awesome.  Not sure whether to wish you bad skiing weather or not.  Looks like you'll win either way.  I'm enjoying my build so far.  Maybe too much, in fact.  I like to enjoy this phase of it because I know it will pass and then I will have years to enjoy the results. 

I will try to get some "progress" pictures up this weekend.

Title: Re: Pending Paramour Build
Post by: Grainger49 on November 03, 2011, 01:30:11 AM
The best 76s I ever bought were from Tube World.  No, they don't need to be matched.  As a matter of fact you can buy singles pretty cheap.  When you buy a pair the price triples.  So buy up some singles.  I have run mismatched, by manufacturer, tubes with no problems if the tube didn't have a problem.
Title: They Live!
Post by: porcupunctis on November 10, 2011, 04:35:09 PM
The Paramours have come to life and are currently driving a nice hi-Rez version of Dark Side Of The Moon through the horns in my listening room.  Nothing "broken-in" yet but they sound fantastic.  I haven't even installed the Obligattos yet.  I will have to pick those up at the UPS facility on Saturday.

In the meantime, I'm just sitting back and really enjoying the Paramours.

I know I've been promising pictures for a while now, but this weekend looks good for a little photo-shoot.


Title: Measuring Hum
Post by: porcupunctis on November 12, 2011, 05:23:16 PM
If my Fluke 112 is accurate at this level, I still have about 7mv of hum on each amp.  This is after the C4S upgrade. 

My speakers have a sensitivity of 94db.  I can clearly hear the hum with my ear near the speaker but barely when I'm at the listening point (and only when all other ambient noises are quiet).  It's not really affecting the listening experience but I'm concerned that maybe I have a problem that I need to track down like a bad solder joint or something. 

Both amps are measuring the exact same, so whatever I've done to one side has been faithfully duplicated on the other (in reflection). 

Dang, they do sound good, though!
Title: Re: Pending Paramour Build
Post by: Grainger49 on November 13, 2011, 01:51:23 AM
Randall,

My speakers are 94dBW sensitive too.  I have not trimmed the hum pots after a recent tube swap and have about the same hum you have.  I haven't moved my hum pots to the top plate, yet.  I assume you did. 

The thing is I can hear the hum at my speakers but not at my seat so it isn't a pressing problem.  I'm surprised you have hum at or above mine.
Title: Re: Pending Paramour Build
Post by: Doc B. on November 13, 2011, 06:03:32 AM
If that is an RMS reading it is high, if it is peak to peak it is about average. It's most likely RMS on a Fluke I think, but you really need a scope to see what exactly the noise is that is being added together to create that number. All the hum pot nulls is 120Hz, if there is other than 120Hz noise present it won't affect it, and that can throw off the measurement.
Title: Pictures First
Post by: porcupunctis on November 13, 2011, 10:58:38 AM
This one shows the two Paramours.  You can see the mirror finish and the mirror build.  Wardsweb is awesome and I stole his ideas shamelessly.

I still plan to do some finish work on the transformers but I'm waiting to see which ones I end up with.  I may upgrade in a few months.
Title: The hum problem
Post by: porcupunctis on November 13, 2011, 11:20:38 AM
I think I located the hum problem and confirmed something that I suspected all along.  I took Doc's suggestion and put it under the oscilloscope.  Nothing too interesting at first.  It told me the hum was 60Hz and it's RMS was 5-6 mV.  This is very close to what I had measured with the Fluke.

After taking the measurements, I shut the amp off.  That's when I noticed something really odd.  The 60 Hz RMS reading on the scope actually went up.  UP?  to about double what I had when the amp was on.  I finally had to unplug the amp from the wall before the reading fell down to the 1-2 range.

The power cords that I received with the kits looked suspicious from the start but I went ahead and used them anyway.  After all, I plan on mounting an IEC connector on the back and will go to something else in the near future anyway.  So the wire colors on the power cord didn't match the instructions.  No big deal.  I know which is which.  The power cords have zero shielding.  Nothing.  I think they were designed to attach to a buzz saw or something.  They are long and massive and nothing like the manual describes. 

I will try an experiment sometime this week with a properly shielded cable and see what happens.  Right now, this is my prime suspect.
Title: Hum
Post by: porcupunctis on November 13, 2011, 11:23:48 AM
Doc warns everyone about buying second-hand kits.  If the power cords and the 15K resistors are the only issues, I think I'll be OK.
Title: Close Up
Post by: porcupunctis on November 13, 2011, 11:27:41 AM
Here is a close up showing the fuse holder and the hum pot mounting.

It also shows the odd mounting of the hole shrinker.  I mounted it on top to hide the regularities of the hole punching operation.  An unintended side effect is that it give the driver a little pedestal so it doesn't look so small up against the 2A3. 
Title: On the mirror build
Post by: porcupunctis on November 13, 2011, 11:46:57 AM
There is some challenge to the mirror build, but it really wasn't that bad.  Once the hardware build was done, I labeled all the connection points just like the manual says.  On the mirrored Paramour I only had to reverse two of the terminal strips.  That was 16 - 20 and 21 - 25.  These ended up being labeled right to left instead of left to right.  The two tube sockets just have to be labeled what they are, you can't transpose the tubes.

I actually built both amps at the same time.  I would solder one wire or part on the "correct" amp and then make the same connection and solder on the "mirror".  At each step, I stopped, pondered, considered, reconsidered, and re-read the manual until I was certain that it was perfect. 

The C4S upgrade actually simplified most of the build and I wish I had just put it in to begin with. 

Since there is at least one other Paramour I kit out there in the wild maybe this will help someone who is giving the mirror look a consideration.  Since I had purchased my kit second-hand, I wasn't too worried about voiding the warranty.  I knew it was up to me to get these babies running.

This experience has gotten me studying the Paramount underbelly.  These would mirror along the short edge and not the long edge like the Paramours.  Somebody has surely tried this already. No?
Title: Re: The hum problem
Post by: Paul Joppa on November 13, 2011, 02:56:21 PM
... It told me the hum was 60Hz and it's RMS was 5-6 mV.  This is very close to what I had measured with the Fluke....
If it's actually 60Hz then the hum pot will adjust it out. Also if it's 60Hz, consider the possibility of nearby transformers which might have a magnetic hum field around them.

Also, make sure the 12AT7 heater pin 9 is grounded to the chassis at T14. In the original build the heater power floated; I don't think this grounding made it into the manual. And while I am reminiscing about this amp, make sure the 499 ohm grid stopper at the 2A3 pin 3 goes to T17, and so does the 270K grid resistor and the 0.1uF coupling cap. Only the stopper goes to tube pin 3, nothing else. The instructions as printed were wrong - I had forgotten these until I checked my ancient marked-up schematic. They came up on the old forum but that's a lot to wade through. Here's a link to the old forum, archived on Audio Asylum:

http://www.audioasylum.com/forums/bottlehead/bbs.html

You can do a search on "Paramour" and get the 200 posts thought by the search algorithm to be most relevant. The algorithm is not very smart though.  :^)
Title: Re: Pending Paramour Build
Post by: porcupunctis on November 13, 2011, 04:36:29 PM
I added the ground wire from pin 9 to T14  Then moved the 270K resistor off A3 to T17.  Everything else was as you described.

The scope doesn't report any 60Hz signal.  The RMS is hard to read because it wanders too much but I see some 1, 2, and 3 readings now and then.

What is most important is that when I hooked them back up I had to get my ear right on top of the cone before I could hear anything.  When I step back to my listening position, I hear nothing from the speakers. 

I think I got it now.

Thanks Paul.

Title: Re: Pending Paramour Build
Post by: 2wo on November 13, 2011, 06:29:32 PM
Congrats, The mirrors do look nice ;). I think your "stop and ponder" approach has you well set for this game.

 Are those arrowheads?...John 
Title: Re: Pending Paramour Build
Post by: porcupunctis on November 14, 2011, 03:59:19 PM
Thanks John.  Yes, those are arrowheads.  Wal-mart specials.  I think I was able to buy enough of those to handle five boxes (4 feet each) for about 5 or 6 bucks.  I got the suggestion from Wardsweb.  I have to give credit where credit is due.  I left the black anodize on, though. 

Title: Paramour Impressions and next steps
Post by: porcupunctis on November 17, 2011, 03:25:49 PM
At this point I probably have 20 to 25 hours of listening in on the Paramours.  Impression?  They are wonderful.  I had been listening to a S.E.X. amp with full nickel output TFs so when I switched to what is basically a stock Paramour I didn't expect to be blown away.  At least not until I get around to some upgrades.  The thing is, they are really holding their own in the starting position.

The upgraded S.E.X. and the stock Paramours are both great but in different ways that I'm not sure I can describe.  The full-nickel S.E.X. I think wins on clarity and low (none) background noise.  The Paramours have some noise if you go listening for it and they seem to win on the low end with what seems like a little more bass extension and I think they present a better "stage". 

I haven't even broken in the stock caps yet and the Obbligatos have finally arrived.  I'm still waiting on some resistors to come in that were missing from the C4S upgrade.  I don't even want to mention how I worked around that one.  I will probably try Grainger's cap break-in technique before I go back under the hood.

There is also work to be done adding the IEC connector or maybe just running the power cord through a hole in the chassis.  Finally, there is the potential Iron upgrade and driver tube change. 

At this rate, I will never get around to the Crack and Seduction builds that are waiting in the garage.