Paramount Soft Start Retrofit

[Lee Hankins]

Last night I finished installing the Paramount soft start retrofit kit.  As usual the excellent instruction manual made the retrofit an easy build.  But, because of all the modifications that I have made to my Paramount the build was a little more complicated, actually a real pain in the ass.  A stock Paramount would not be difficult at all.  

Put the Paramounts (300B version) back into the system this morning, I had forgotten what a wonderful amp the Paramount is, and that in the right amp the 300B is an excellent sounding tube.  I have been playing around with several amps (4) with the 45 power tube.  Thought I had found the ideal sounding power tube, but after listening this morning to the Paramounts with the soft start retrofit installed has made me rethink my previous assumptions.

Now the fun begins, listening and tube rolling.  Highly Recommended upgrade, one of the best "bang for the buck" that I have encountered in audio.

(https://lh3.googleusercontent.com/__2uyTsETJF0/TWBLct4MDEI/AAAAAAAAAPk/CuTupkaOmls/s1024/P1010775.JPG)

Cordially,
Lee Hankins      (http://)

[John Roman]

Nice work Lee!

[johnsonad]

Finished the first amp today myself.  Took a lot longer than expected.  Missing one part to finish the second amp this weekend...  Converted them over to 2A3 and put the Magnequest iron back in.

[Jim R.]

Now if you guys can get yourselves a pair of late 1950s Ericsson or Siemens gold pin 2C51s, I think you'll like what you hear.  Personally, I like these much better than either the WE 396As or the Bendix 6385s.

-- Jim

[shelby1420]

Now if you guys can get yourselves a pair of late 1950s Ericsson or Siemens gold pin 2C51s, I think you'll like what you hear.  Personally, I like these much better than either the WE 396As or the Bendix 6385s.

-- Jim

I have a set of both the WE and the Siemens gold pins to try when my Softstart arrives!!!  I would love to hear your thoughts re the Iron upgrade Johnsonad, thinking about these for my 2a3 amps BH-5 Full Nickel Outputs (1pr) | BH-6 Plate Chokes (1pr).........

[Lee Hankins]

Jim, I have 6 GE (2-1978/4-1988) and 3 WE396 (1988), I definitely do not like the sound of the WE396 in my system, the GE's have more detail, IMHO a better sounding tube.  The 1978 GE sound a little better to me than the 1988 version.  Will have to get a pair of Ericsson or Siemens tubes to try.

Lee Hankins

[johnsonad]

I've got a stash of tubes waiting for these amps but not the Siemens or Ericsson you wrote of.  I am hoping one of these pairs has good synergy with my system.  Anyone else pick up the Russian tubes?  I've got a couple of pair to try in addition to the usual suspects. 

As far as iron goes, Mike's makes a difference.  I wrote in a different thread that I couldn't get the bass right with the 300B tube (among other reasons).  Honestly I don't care for the tube much and prefer the 2A3 and 45 to it.  I've got BH-7 PC's now and if I like the sound then I may pick up the BH-6.  If you are going to stick with the 2A3 tube you may want to get the BH-6 from the get go.  Trying out the Auricap on PJ's recommendation too.  I like what they do with the Eros.   

[Jim R.]

Hi Johnsonad,

I had a similar problem with the 300b paramounts I had on loan here -- just the bass was a bit too thick, and with my speakers being a resonant type, they sounded thick and slow in the bass, which these speakers and the paramount amps are definitely not.

If you need that kind of power, have you considered building the paramounts as a 300b with a 2.5v filament and then using either the JJ or Sophia high power 2a3s, or what Sophia calls their 2.5v 300b?  That filament voltage change can possibly make a difference in this configuration.  I haven't tried it as I don't own the paramounts, but if I did get a pair, this is probably how I would first try them.

Can I ask what speakers you have?

-- Jim

[johnsonad]

Hi Jim,

I'm using Altec Model 19's which are around 100dB efficient.  It probably was an impedance issue though I'll never know.  Currently I have a different 2A3 amp which really makes them sing.  I'm hoping the 2A3 Paramounts can offer just as much if not more. 

Aaron

[Jim R.]

Hi Aaron,  Yes, another "live" cabinet design, at least not a "dead" one,e, aone, and where, in my opinion, the 300b with it's thicker upper bass/lower mid response can make the cabinet sound "slow".  But that's just me, so certainly not a universa phenomenon.

I too just love the 2a3/45 sonics.

-- Jim

[Paul Joppa]

For the Paramount, in 2A3 or 300B form, it may pay off to experiment with the parafeed capacitor value. Anything from 2.7uF to 10uF is reasonable, and the results will be different with different speakers. There's another thread going on this right now.

[johnsonad]

These came in today and a picture doesn't do them justice.  The build quality is amazing. 

For PJ, my first amp is running 475 at A2 with 123v at the mains.  I'll recheck this once the amps are on regulated 120v but at what point do you consider it high? 

[patm]

to Johnsonad

I agree about the build quality on the EML's I bit the bullet and got a pair of 300b mesh plates. 50hrs in and sounding amazing. The difference between the mp's and the winged c's I changed is like the difference between a 3mp photo and a 20mp photo, much more of everything.

Pat

[Paul Joppa]

...
For PJ, my first amp is running 475 at A2 with 123v at the mains.  I'll recheck this once the amps are on regulated 120v but at what point do you consider it high? 

Sorry, I can't recall the context - I think there's another thread involved? I do have a bad cold right now and my brain isn't working very well. I deduce those are EML mesh 2A3s running in a Paramount, hopefully with the soft start driver board. Please be careful to adjust the driver plate voltage as described (158 volts!), and to ALWAYS let the caps discharge for 20 minutes after switching it off, so that the soft start works correctly. Otherwise you can damage those tubes very swiftly.

If I was talking about plate dissipation, you are fine. The 2A3 dissipates more than 15 watts only when the plate voltage is greater than 512 volts; at 475v (and with the driver properly adjusted) you should have 205v at the hum pot center tap, and would dissipate about 12.8 watts.

[johnsonad]

Thanks Paul.  I hope you beat that cold soon! With luck and a trip to Akihabara for the missing part, I'll have these amps up and running this weekend.