Bottlehead Forum
Bottlehead Kits => Legacy Kit Products => Topic started by: Jim R. on January 27, 2011, 04:17:50 AM
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My new paramour II amps arrived yesterday and I just got to unpacking them this morning. Very nice. They appear to be a very clean, very stock build (though I can't see the caps and such) but there is no repurposed plate choke, etc. They were very well packed and only suffered very minor shippoing damage. That is that both front screws on both plate chokes had loosened and fallen out, and on one amp one side of the OPT also lost it's screw. Other than slightly bent tabs, there appears to be no damage, and all hardware was recovered.
I'll send some pics later, but the amps are black with a satin finish (not sure if it's paint or dye), and the tops are clear-coated stock aluminum, and the bellends are black. There are bottlehead badges front and center on the base of each amp, and feet are the stock rubber ones.
I hope to make the minor repairs, give everything a good going over, and then give these a try in place of the Fis and leave them there for a couple of days and roll a few tubes through them.
I'm very pleased with my purchase and very much looking forward to giving them a listen.
Poics to come later...
-- Jim
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Well, I've tried many times now to post some pics and they simply won't post. Whether it's 1, 2, 3, or all 4 I have, and they are all between 52 and 63 mb and they still won't go, so not sure what's up, but I've not had this problem before.
Maybe I should try a different browser...
-- Jim
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Well, I've tried many times now to post some pics and they simply won't post. Whether it's 1, 2, 3, or all 4 I have, and they are all between 52 and 63 mb and they still won't go, so not sure what's up, but I've not had this problem before.
Maybe I should try a different browser...
-- Jim
The easiest way to post pictures is to use a media host. I use image shack. They are free, you should check them out.
http://imageshack.us/ (http://imageshack.us/)
Once the pictures are uploaded copy one of the links (I like to use the direct link) and use the "insert image" button on the bottlehead forum.
Use the preview button to verify your image will look OK. And then hit post.
I hope this makes sense and I hope it helps.
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Hi and thanks. I happen to be blind and most of those photo sharing sites don't work with my access technology, so I generally can't use them very effectively.
I just enabled my MobileMe account last night, and hopefully that may let me do this, but that is going to be a learning curve, and I'll have to ransfer things over to my Mac first -- the mobile me toolbar for windows doesn't work very well either.
I tried again several times last night with FF instead of IE, and still got the same results.
This all used to work fine for me, so not sure what is up.
-- Jim
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You said "...they are all between 52 and 63 mb ..." - those are quite large. I don't know of there is a limit, but it seems likely. I know that, when pictures are posted to facebook for instance, they get reduced both in resolution and by compression (to .jpeg format) - usually 30 to 100kbytes is enough. I can do this in Paint, using "stretch/skew" and specifying a stretch factor for horizontal and vertical. There are probably better ways, I'm no expert.
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Oy, I just went through all that to find that somebody else was posting and my post went to the big bit bucket in the sky.
It's a 7.5 mp camera, and I send the pics to myself using the image size reduction option -- the only thing I've found that I can work independently. I also ment Kb, not Mb :-). Ok, I'll try again...
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi244.photobucket.com%2Falbums%2Fgg7%2FGrainger49%2FFor%2520Jim%2520R%2FParamours-front.jpg%3Ft%3D1296306647&hash=df3a46e3e70f49dc334b3ee322f842c7d73a0c99)
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi244.photobucket.com%2Falbums%2Fgg7%2FGrainger49%2FFor%2520Jim%2520R%2Fparamours-guts.jpg%3Ft%3D1296306558&hash=875e74734ccea947f7db4e680d9eff1595a5230f)
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi244.photobucket.com%2Falbums%2Fgg7%2FGrainger49%2FFor%2520Jim%2520R%2Fparamour-left-guts.jpg%3Ft%3D1296306603&hash=7cb428bec6c649f036c98912b055b7ded8ceb730)
(https://forum.bottlehead.com/proxy.php?request=http%3A%2F%2Fi244.photobucket.com%2Falbums%2Fgg7%2FGrainger49%2FFor%2520Jim%2520R%2Fparamour-right-guts.jpg%3Ft%3D1296306623&hash=4bbb8286a4a766965dc131af30d5b4ded2128c67)
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I see pictures!
What is the base that you have made for your, I guess, Stereomour? It is beautiful!
Your new, to you, Paramour IIs seem to have a giant copper clad Parafeed capacitor. Man, I'm jealous of all that room under the hood of the IIs. Now you need to convert them to 76 drivers. I've got instructions.
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That wood for the base to the right is beautiful. I have a whole stack of nice spalted maple just waiting for something to do with it. You just gave me an idea.....
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Spalted maple can be gorgeous. The top of my Tele is spalted maple. Read up about stabilizing the punky parts before you get too deep into a project with it. Seems like the most common way to firm up the soft parts is soaking them with crazy glue.
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Hah, that's funny, because I don't see the pics or the links, just the modify link. It's always interesting :-). I'll try later with Firefox to see if it shows me the pics.
As for the stereomour base, that's spalted birch, and the walnut trim top and bottom was because those edges were much too punky to work with -- even rubbing your finger along them made the wood disintegrate. Right now it only has one coat of General Finishes Seal-A-Cell, a prep coat for the Arm-R-Seal coats to follow. The show chrome top was done by New England Chrome plating. From what I can feel and from wht my friends tell me, it is beautifully done.
Grainger, I'm probably not going to conver to any other driver tube until I convert the entire ampps to the SR45s, which is the reason I bought these in the first place. I'm going to replace the screws today and put these upstairs with the Cornwalls for a while and just enjoy them as they are. Big copper caps, eh? Hmm, wonder if they're Jensens.
I just today got a pair of anos Ge JG 12at7wa triple mica black plates, and I'll be giving those a try in these amps once I make sure they are functioning correctly.
Funn stuff!
Thanks all for the feedback and help from Grainger and Doc. Such a great place this is!
-- Jim
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Looks like the stock iron complement. When you do the upgrade, the plate choke will become a power supply choke. It will replace the 270 ohm 5 watt resistor that is across the front of the power supply (parallel with and adjacent to the front of the power transformer). It will mount behind the power transformer - you can see (feel) the mounting holes in what is now a big empty space.
It also looks like a neat and clean build.
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Paul,
Yes, that was my first impression -- that it felt like a very clean build. That and I was also expecting that it would be like the s.e.x longer front-to-back layout, not the wider layout. Also like the pretty much goof-proof 4 in sockets.
Got diverted today, so will give them a listen tomorrow.
-- Jim
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Ok, this is not at all what I was expecting... As Herb Reichert once said, I never met a 2a3 I didn't like. Well, I had always heard that these were good little amps, and very good for the money, but... I was not expecting them to be this good! I was listening with one Fi and one Paramour, and tomorrow will get the second working. Had a little problem with one amp in that when I turned it on, it gave a faint hum, a mild pop, and then a very strong 60/120 hz hum, and no residual music iunderneath, and the hum balance pot had no effect. Ok, open input, I figure. Took the amp out and put it back on the desk, flipped theplate over, and sure enough, a broken lead on the center pin of the RCA. soldered it back and the same thing. Jumpered itto ground and no hum, so I'm guessing that the RCA is bad somehow, so tomorrow I'll reaplace it with one of the leftovers from the s.e.x. or crack kits and then see what happens.
Back to the listening... Could these actually be resolving more and with a cleaner, airier top end than my Fis? Perhaps, but that will have to wait until I have both amps playing together. So, maybe there a bit more plummy in the bass, but they seem to go as deep, and the soundstage and ambient cues are as good (maybe better?) Hmmm, need more time, but I'm more than impressed at this poin.
And one final thought for tonight -- these are supposed to be "noisey" amps, relatively speaking of course. Well, with the hum pot dialed in they are as good or better than the Fis, but more 120 hz than the 60 hz of the Fis -- but certainly quiet enough for comfortable, effortless listening.
And the Paramounts go further up the scale than these? Hmmm, this isn't supposed to happen -- the original paramour II kit cost less for the pair than a single OPT
on my Fi amps.
BTW, the JJ 2a3-40 sounds lovely in these.
-- Jim
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Hi Jim, The copper caps appear to be Obbligato, A fine choice. I use them in my SR-45,Russian K-40 as the coupling cap.
When I built the amp, I set the hum pots to the center and never bothered to adjust them. Hum on my 96 db speakers is not an issue. Plus I swap tubes in and out and am too lazy to dial each one in.
To prevent the lost post syndrome, I am now copying the text to the clipboard, before I post, just in case...John
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Hi John,
Thanks for the ID on the caps, and yes, I would say from my first listen that this is how I would describe the largest differences between the musical presentation -- the Fis sound like a direct coupled amp, which they are, and the Paramours sound more like a cap coupled amp, and even if I didn't know they were copper PIOs, I probably would have guessed it.
Very much looking forward to getting ammp number 2 up and running so I can get the fully representative experience.
Excellent idea on the clipboard too!
Guess I better call Eileen today and get a manual on the way in case there is more going on than the input wiring.
-- Jim
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Got a little care package from BHQ today with my new powr cord kit, a replacement 9 pin socket and a hole shrinker, and the paramour II manual... and thanks, Eileen for the kisses! :-)
I'll look over the manual tonight and then will get to repairing the broken tube socet tomorrow.
Can' wait to hear both amps together.
-- Jim
.l
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So, if you have gobs of gain I wrote up Paramour II 12AT7 to 76 driver conversion instructions. I did it for the Paramours I have (last of the originals) and Doc sent me the Paramour II manual so I could write up the same conversion for it. It has been confirmed by a couple of Bottleheads who have followed my directions.
It looks cool having two Coke bottle tubes on top, not that it matters to you, and it sounds very good.
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Grainger,
I probably won't change the driver tube until I do the SR-45 conversion, and then it will probably be a 6dn7, and if possible, maybe a 9-pin to octal adaptor for the original 6cm7 (as long as it will be plug and play with no bias or CCS adjustments needed.)
I think I have the one bad amp somewhat jury rigged and should hopefully be able to test it today. I'm supposed to be getting my new power cables today, and then I can put the system backtogether and give it a spin, and with my new setup, I can swap power amps in a matter of minutes.
-- Jim
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Well, my kludge to fix the tube pin on the driver tube socket worked -- for about 5 minutes. Enough to hear what I was looking for.
I've been running my office system with 4 amps in rotation the past couple of weeks and after all is said and done, both my EL84 Carina and the Paramour IIs have come out on top, so the
Fi monos and the Ampino will be on the block. Nothing wron with them and they are both great amps in their categories, but the rina and the Paramours just sound better in this room with the speakers I have.
Tomorrow I'll have to get serious and fix the bad tube socket on the one paramour once and forall.
PJ, you did a remarkable job on this amp, especially considering what it sold for! Color me impressed.
-- Jim
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Ok, I think I have made a decision and have decided to upgrade the paramours with the stock opts from the paramounts, once I convert those ver to d2a3s with the soft start boards. The problem is that I don't know what the inductanceof the stock paramount opts are, and I'd like to try to pick the right plate choke for the job.
What I would have available are the stock PCs from the s.e.x., paramours, and paramounts and/or maybe the stock PCs from the stereomour -- depending on which amps I put the bcp-15 (50 mA version) in.
It looks like with a padding resistor in the paramount psu, and the soft-start boards, I will be able to use the bcp-15s in the paramounts, so the original paramount PCs are, I'm guessing, the best match for the paramount OPTs in the paramours.
Am I missing anything with this scenario? I just figure I can turn over the paramours with better iron and then anybody who needs some original specos can have the ones out of the paramour and/or s.e.x. mps.
-- Jim
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OK, we may need to archive this somehow. I can't believe that it's never been compiled before!
Paramount stock plate choke: 24H, 70mA, 330 ohms
Magnequest PC-7 27H, 70mA, 430 ohms
Paramour II (obsolete) stock plate choke: 10H, ca. 60mA as plate choke, 270 ohms
Magnequest BH-6: 40H, 50mA, 540 ohms
Stereomour stock plate choke: 20H, 50mA, 590 ohms (black wire tap)
SEX stock plate choke:30H, 35mA, 750 ohms
Magnequest BH-2: 50H, 40mA, 540 ohms
(Not yet released) SEX-2011 stock plate choke: 40H, 35mA, 830 ohms (red wire tap)
(The parafeed capacitor is estimated from the choke inductance, not the output transformer inductance which is generally so much higher as to have little effect.)
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Thanks, Paul. Very useful information to have.
-- Jim
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Decided to hold on to these after all, but will build them as basic 45s and then maybe later think about upgrading to SR-45s. I will be ordering an exo-45 and bpc-15 40 mA, and will take it from there. Yes, will have to rework the operating point, but that's fine.
-- Jim
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I'm curious, does the Xl of the choke equal the Xc of the parafeed cap giving a complementary complex impedance?
I will have to store the choke data somewhere.
. . . (The parafeed capacitor is estimated from the choke inductance, not the output transformer inductance which is generally so much higher as to have little effect.)
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I'm curious, does the Xl of the choke equal the Xc of the parafeed cap giving a complementary complex impedance?
I will have to store the choke data somewhere.
. . . (The parafeed capacitor is estimated from the choke inductance, not the output transformer inductance which is generally so much higher as to have little effect.)
That's part of the story. :^) The complementary impedance can only happen at one frequency, and that frequency is not arbitrary.
The first thing I did was to simplify everything to just the source and load resistances, the plate choke inductance, and the parafeed capacitor. The main assumption is that the output transformer inductance is high enough that it appears as a resistance when loaded by the speaker which itself is assumed to have a constant resistance with no reactance. These assumptions make it clear that the results are a starting point, not the final word!
Then I non-dimensionalized the mathematics - normalizing all reactances to the load resistance and the frequency at which the normalized inductive reactance is unity (XL/R = 1). The capacitive reactance is similarly normalized. Then I ran some simulations, looking at the load on the tube as well as the frequency response. That's because if the load on the tube gets much lower than the normal design value, the tube will distort even if the transformer does not. The best compromise in my judgement occurs when XC/R = 0.5, which after undoing the normalization means C = 2*L/(R squared). That's my starting point value though I may adjust it for various practical reasons in specific designs.
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Thanks for walking me through the math. It has been several decades since I have done any of this.