Pending Paramour Build

[porcupunctis]

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.

[Paul Joppa]

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.

[Grainger49]

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.

[Grainger49]

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.

[porcupunctis]

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.

[Grainger49]

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.

[2wo]

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     

[porcupunctis]

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,

[porcupunctis]

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.

[Paul Joppa]

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.

[Grainger49]

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,

[elcraigo]

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.

[Grainger49]

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.

[porcupunctis]

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.

[Paul Joppa]

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