Princeton w/o reverb or tremolo

[kkregsg]

I'm interested in building a Princeton amp, either a 6G2 or an AA964 without the tremolo. I'm fairly new to building- I can easily follow layouts and schematics, but I'm not yet educated enough to look at the schematic and know if just leaving out the tremolo circuit as shown will work, or if I'm missing some connections that will need to be completed. In other words, I can mimic, but I'm still lacking on understanding the complete circuit and it's building blocks.

I'm working on my first build, a Spitfire clone, and know to discharge caps, work one handed, and that a chopstick is my friend. I have the Dave Hunt book and Blencowe's preamp book, but I tend to spend time soldering rather than working the math. I've successfully built a number of pedals, and a few small solid state amps for hard of hearing friends to use with earphones/TV.

Any advice would be appreciated, and any suggestions as to material to read for learning will be heartily consumed.

[kkregsg]

In the interest showing some effort, is it as easy as leaving off the tremolo as shown in the attachment? How do I then reclaim the open triode? Will this affect component values?
Expiring minds want to know.

[Blackburn]

My opinion is that the perk of the Princeton is the trem, or verb and trem with the Blackface, because the overdriven tone (to me) leaves a lot to be desired. If you're dead set on that tone, fine, I say build one exactly the way you want. If so, you'll need to modify the bias circuit a bit and not much more than that.

If you want my advice, build it with just the trem and change the cathodyne inverter to a LTP and you're set. You may or may not know this, but the bias vary trem of the Princeton and Vibrochamp are quite different from the rest of the Blackface line and sound wonderful, if you dig that sort of thing. Check out YouTube for examples. If you like this idea, I can direct you to a modified schem and you can go from there.

David

[xtian]

If you like this idea, I can direct you to a modified schem

Yes, pleez.

[M Fowler]

Here is a schematic from Hoffman forum.

[Blackburn]

Okay, I couldn't find it on the web, so I made this for you guys. Excuse the crude nature of my work, but this is it. You can choose to keep the presence and go even further than that by ditching the resistor for a mid control instead, but this should suffice and the rest is up to you. A few other things like upping the filtering of the 6V6s and adding screen resistors would do you good. Other than that, I can't think of anything else to add. Hope you like.

David

[kkregsg]

Thanks for the quick replies. Yet again M Fowler has supplied needed info. Thanks as always.
Blackburn, I appreciate your thoughts. I rarely, if ever, use tremolo. That's my reason for asking about building without the tremolo. I was looking for something between the Champ and a Deluxe with a nice clean. Yes, I'd be interested in the modified schem.

[DocJames]

Has anyone built that PR with the extra gain stage? If so, what are your thoughts on the breakup characteristics?

[kkregsg]

I'd be interested in a schem on that, too, if any one has one. Anything worth researching is worth over-researching! I might learn something in spite of myself.

[M Fowler]

Here is a thread on converting princeton to ODS that has gain stages

https://tubeamparchive.com/viewtopic.ph ... ght=#16953

[DocJames]

That looks really interesting. I wish the sound files still worked, I'd love to hear how that sounded.

[kkregsg]

Wow. MFowler, is there anything you don't have on your computer? I'm archiving/ bookmarking everything I run across, but it looks like it will be awhile before I'm in the same league. Now if I just had the cash to build everything on my list.

[M Fowler]

Wow. MFowler, is there anything you don't have on your computer? I'm archiving/ bookmarking everything I run across, but it looks like it will be awhile before I'm in the same league. Now if I just had the cash to build everything on my list.

No

My computer is full of schematics and layouts. Just backed it all up because I don't want to start over.

I haven't even shared the top secret stuff TAG members have entrusted me with.

[kkregsg]

I'm just happy for all the "usual" stuff you've shared.
My computer is full of any helpful bit of information I can find on amp building, pedal building and general electronics. I back up often, because I would be beside myself if I lost what I've been able to scrape together. Some day I'll get it all read, and at least partially learned.
It's like learning guitar- the more you learn, the more you see there is to learn.

[Craig B]

If you build the Blackburn version and it is not clean enough, you can sub in a 12AT7 for the phase inverter. If that is not clean enough, swap in 47k/47k plate resistors instead of 82k/100k. On the other hand, if it is not rough enough, there's that unused triode...
Good building,
Craig