My Paramount experience

johnsonad · 16970

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Offline johnsonad

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Reply #15 on: April 24, 2011, 06:07:55 PM
A brief update:  The Triad chokes have been in for a couple of weeks now and I

Aaron Johnson


Offline Grainger49

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Reply #16 on: April 24, 2011, 11:31:07 PM
I think you have heard a number of things I heard as well at Paul's.  But soon after putting in the chokes we improved all the iron with MQ BCP-15 and all nickel output transformers which multiplied this effect by a large margin.

Next you need to buy a pair of Clarostat 10 turn pots, 4 resistors and a pair of tube sockets to bring the bias adjustment to the top of the chassis.  This is a mod of convenience rather than a sound improvement.  But you will never need to flip it over to adjust the bias on the driver tube (assuming you have the soft start board installed).



Offline Jim R.

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Reply #17 on: April 25, 2011, 12:59:06 AM
Aaron,

Sounds lke a worthwhile mod, but one I'll probably wait until my speakers are done before I try it.

Grainger, just curious why you used a tube socket for test points when tip jacks are available very cheaply and in a variety of colors?  Or was there an existing tube socket hole that you could fill?

-- Jim

Jim Rebman -- recovering audiophile

Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).

s.e.x. 2.1 under construction.  Want list: Stereomour II

All ICs homemade (speaker and power next)


Offline Paully

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Reply #18 on: April 25, 2011, 01:36:02 AM
If there was a better option, we just weren't aware of it.  We both have had Dynaco's as our main amplifier in the past.  I think that that concept for setting bias is just what we had in mind so that is what we used.  We looked around for some other options but didn't see anything that really worked for us.  The tube socket kept voltages below where one could easily stick a finger so it was good enough for us and an 8 pin mini-socket fit.  So we used it.



Offline Grainger49

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Reply #19 on: April 25, 2011, 02:16:07 AM
Jim,

I knew there were such things but I didn't locate them anywhere.  I didn't use the search parameter of "tip jack."  The tube socket was used because initially we thought there were 3 or 4 voltages to measure.  We also had thought that a socket would allow us to measure the B+ directly.  Paul Joppa was uneasy with even a tube socket with high voltage on it all the time.

Turns out there are only two voltages to be measured.  As Paul Joppa configured it the two should be the same voltage.  This simplifies the adjustment to: measure between the two pins and adjust to zero volts.
« Last Edit: August 22, 2011, 12:53:51 AM by Grainger49 »



Offline Jim R.

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Reply #20 on: April 25, 2011, 02:53:46 AM
Sounds good guys -- just didn't know if there was a particular reason for using a tube socket, but I understand why now.  I'll probably "borrow" the idea when it's time, but as I have plenty of spare tip jacks, and only two are needed, well, I'd rather drill a pair of 1/4" holes, than one larger one -- things are going to get crowded in there anyway.

-- Jim

Jim Rebman -- recovering audiophile

Equitech balanced power; uRendu, USB processor -> Musette DAC -> 5670 tube buffer -> Finale Audio F138 FFX -> Cain and Cain Abbys near-field).

s.e.x. 2.1 under construction.  Want list: Stereomour II

All ICs homemade (speaker and power next)


Offline johnsonad

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Reply #21 on: April 25, 2011, 08:39:31 PM
Well said Jim. The more mods we do the more crowded it becomes :)  I may do this mod too at some point but I don't roll tubes often enough to justify it in the long term. Thanks for the recommendation! 

Now if Paul would release the schematic with relays and film caps in the PS........ ;^)

Aaron Johnson


Offline Grainger49

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Reply #22 on: April 26, 2011, 12:44:44 AM
We have completely hijacked Aaron's thread.  We ought to be in Paully's thread:

http://www.bottlehead.com/smf/index.php/topic,1635.0.html
« Last Edit: April 26, 2011, 01:07:10 AM by Grainger49 »



Offline johnsonad

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Reply #23 on: August 21, 2011, 06:14:41 PM
As all good things must come to an end, so does my ownership of a great pair of Paramounts.  My Altec Model 19

Aaron Johnson