Pending Paramour Build

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
 
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. 
 
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.
 
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,

 
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".
 
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
 
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.
 
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.

 
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.
 
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.


 
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!
 
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.
 
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.
 
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.
 

Attachments

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.
 
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. 
 

Attachments

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?
 
porcupunctis said:
... 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.  :^)
 
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.

 
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