Soft start shunt update?

[Doc B]

The manual that I am currently writing is specifically for retrofitting this kit into the current version of the Paramount amps. The next manual I plan to write is one that will be specifically about building the new Paramount V1.1 which will incorporate the soft start shunt regulator into its construction. So the safest list I can give today has just one entry, as it comes the kit parts and instructions are specifically for Paramount. But one could change a few parts values and use it in a variety of applications, in fact the board has been designed as a sort of future universal replacement for a lot of our kits to aid our inventory control. I'm going to let PJ weigh in here on more specifics.

It is difficult for us to know the comfort level of our customers when it comes to how much they are willing to figure out on their own. I get a certain number of folks who ask for very highly documented instructions for one-off customizations of kits, and that is unfortunately not something I really have the time to do these days. That's a major reason for the existence of this forum. As a community we can all work to develop enough info for someone to develop these kinds of special projects that might be tackled by just a few people.

 

[ssssly]

The forum is no doubt one of the greatest assets to this hobby. And your post is actually more or less what I was talking about. Was thinking more a list of which kits have power transformers capable of the extra current draw. And then let those of us crazy enough to dismantle perfectly good sounding amps figure out the rest via the forum.

 

[Paul Joppa]

...
Maybe you or PJ could post a list of kits that this will work with. ...

I'll work on it, but understand, there are nine other kits (counting the discontinued ones) and some of them existed in several different forms. Not to mention that many of them have been modified by their owners! I'll see what I can come up with.

 

[Doc B]

In general a kit that already has a shunt reg and active loads like the upgrade that JT did for the Paraglow would be able to use this kit once modified for the operating conditions. That would include the shunt reg 45 that we did as a limited run - adjusted of course for the 6CM7 tube rather than the 5670. And one could also use the boards themselves in Eros and FPIII.

 

[xcortes]

Funny thing is I'm thinking backwards than the rest. When I rebuild my Parabees and my Excites I will use the driver section from the Paramounts!

 

[Doc B]

I can't quite remember what the circuits for all the 45 variants we came up with over the years were called. Was the Excite a monkey on a stick circuit, where we put the driver tube and its active load under the cathode of the 45? If it is you will want to change it to something more like the Paramount 2A3 - or if you could do the SR45 circuit with some adjustments.

 

[Paul Joppa]

This is a first cut; I'll try to edit it as corrections or other questions crop up.

Original SEX
Based on the DeYoung power transformer version. Should be possible using the existing tube (no 5670) but mounting the board and routing the wiring will require some creativity.
I would recommend upgrading to the TFA-204 output transformer, removing the feedback loop, and changing to dual bias resistors and bypass caps in teh output stage, as long as you are under the hood.

Current (stereo) SEX
Not applicable.

Afterglow
With the DeYoung power transformer, you cannot get to the requisite 100v on the plate unless you change the driver to a 6CG7 or similar low-gain tube. Actual desired voltage will depend on the actual power voltage in your house

 

[xcortes]

Nope

The Excites were a 45 version of the Paraglow. The circuit was very similar to the one published in Valve known aka Simple 45. Direct coupled, C4Sed 45 with PGP 8.1s The article circuit used 5965s(?) paralleled. The BH version used 6N1Ps and there was a II version by JT that SRed the 6N1P.

The OP points were classic RCA's 45 OP.

 

[Paul Joppa]

The oldest designs went through the most changes - this was before we started to use version I, II, III designations for major revisions. This applies to Original S.E.X., AfterGlow, eXcite, B-Glow, and to a lesser extent the parafeed amps ParaSEX, ParaGlow, and ParaBee.

I started to write down some of the changes I remembered, but the post got hopelessly complicated as I kept remembering more changes and revisions. Suffice it to say that, when considering changes to any of these older products, you may have to do some sleuthing to uncover the exact configuration!

 

[Steve_in_NV]

Any shipping date set for this update?

 

[Doc B]

Any shipping date set for this update?

Just waiting for some parts to show up and we'll be shipping.

 

[Steve_in_NV]

Woo Hoo! kit arrived today, I know what I'll be doing this weekend.

 

[johnsonad]

"I'm so excited, and I just can't hide it....."  Not that it's playing but if you can't tell, I'm looking forward to this build