Princeton ODS? Threads? Advice? First D build

[cdc3jj]

I've built a few tweeds, and done mods, etc. I'm thinking about buiding a BF Princeton Reverb from parts salvage and would love to turn it into a 14w ODS. I have a Ceriatone HRM BM and the cleans are good but it's missing the squishy OD. I think I could get 14w closer to the limit than I can 50w.

I searched around and saw some cool builds. Does anyone have a layout for something like this? (I'm not educated enough to build from schematics yet) I'm not concerned about keeping the reverb or vibrato. I'll be building my own cab and chassis so I don't have any size restrictions. Probably use MM OT and a weber PT, as well as their fiber board.

I realize this might be a long shot, but I have nothing but time. And I learn by doing much better than reading. Thanks

[bluesfendermanblues]

....I have a Ceriatone HRM BM and the cleans are good but it's missing the squishy OD. I think I could get 14w closer to the limit than I can 50w.

You really should be able to get the 'squishy' OD tones from the Ceriatone. And by the way, these tones stem from the preamp and not the poweramp. FWIW I can get those tones from my D-style amps with the master on 1 (8 o'clock).

It important to
a) have the OD input trimmer set quite low...the trim in my amps are set around 23k to ground = 9:30 O'clock. And
b) you got to play with a somewhat soft picking attack in order to allow the tone to bloom from time to time.

It's always nice to move into new amp ventures. However, 14W will not get you closer and you need to get the tones from the Ceriatone before exploring a new amp...or you'll just get disappointed again.

[Bob-I]

There's another thread on this topic. Check out the 15 watt ODS topic a-ways down the page. I posed clips of mine.

I used the ODS101 schematic posted on the files page. It's a tight squeeze but possible.

[bluesfendermanblues]

I have an old mesa boogie combo clone, which I intend to transform to a 15w ODS with reverb. This could be my light-weight, grab and go amp.

[David Root]

I will starting on a 50W ODS akin to #13 soon. In a Mojotone BF Princeton chassis and a custom BFPR combo cabinet set up for a 12" speaker. Using '67 Bassman iron out of a very early SF Bassman.

It will be fun cramming all that into the chassis. I didn't notice it until recently but the Bassman OT is just about the same size as a standard Twin OT and way bigger than anything designed for a Princeton. Still it has been done before I know.

[heisthl]

I will starting on a 50W ODS akin to #13 soon. In a Mojotone BF Princeton chassis and a custom BFPR combo cabinet set up for a 12" speaker. Using '67 Bassman iron out of a very early SF Bassman.

It will be fun cramming all that into the chassis. I didn't notice it until recently but the Bassman OT is just about the same size as a standard Twin OT and way bigger than anything designed for a Princeton. Still it has been done before I know.

The key is to do the internal layout work in a graphics program before you start mounting and drilling. Externally even simple stuff like the larger PT clearing the cabinet side cleats or the O.T. placement so it doesn't hit the speaker frame, all have to be considered beforehand to make your build go smoothly.

[Structo]

On your Ceriatone amp did you get the stock transformers on that or did you install your own?
Something that is stressed here that I have been a slow convert to is how important the voltages to the tube plates is.

I struggled a long time and recently went through my amp (Brown Note D'Lite 44) and adjusted the dropping string after I installed a choke.

My amp suddenly sounds more Dumbly.

So check that out on your HRM, also since your amp is HRM be sure you have to HRM stack adjusted correctly and the OD trimmer is set at around 25K-35K wiper to ground.

V1 ~195-200v
V2 ~200-205v
V3 ~ 285-290v

[David Root]

Thanx Heistl. What kind of graphics program would you recommend?

I plan on mounting the iron and sliding the chassis in place then seeing what size speaker interferes with the OT. I would like to put an Altec 417C in but a) I don't have one and b) I don't have a dimensioned dwg of one so that is a bit of a crapshoot. I would imagine it's about the same size as an EV12L but I don't have a dwg of that either. I do have a Weber 12A150 which is a P12N I think. But it's only rated 50W and is not a very Dumbly choice from the extended high end point of view.

I think the OT can be shifted around a bit but there is not a lot of leeway to be had there I think.

[M Fowler]

Henry of course is correct layout is so important.

I learned the hard way about component placement on my Fender Deluxe 90 solid state amp to tube chassis conversion. I ordered another custom slant chassis 19" because I placed everything wrong and butchered that chassis. I'll save it and maybe build it into my own cabinet but want to start with a fresh chassis do the layout precisely this time and create an amp that works well not just thrown together like I did the first time.

[heisthl]

Thanx Heistl. What kind of graphics program would you recommend?

I plan on mounting the iron and sliding the chassis in place then seeing what size speaker interferes with the OT. I would like to put an Altec 417C in but a) I don't have one and b) I don't have a dimensioned dwg of one so that is a bit of a crapshoot. I would imagine it's about the same size as an EV12L but I don't have a dwg of that either. I do have a Weber 12A150 which is a P12N I think. But it's only rated 50W and is not a very Dumbly choice from the extended high end point of view.

I think the OT can be shifted around a bit but there is not a lot of leeway to be had there I think.

Visio works good. but there may be some freeware CAD program that could do it too. RE: O.T. placement: you have to figure that out by just mounting the speaker and chassis and sliding the O.T. around until you find a workable mounting point.

[David Root]

Thanx again H. That's what I figured I would have to do with the OT, and putting the PT on will reveal any interference problems with the cabinet.

[M Fowler]

Here is a Princeton layout from an old post.

[Structo]

Cool!
I may have to convert my 6V6 amp to that.

[David Root]

Thank you! That is very helpful!

[Bob-I]

Thank you! That is very helpful!

It is an amazing little amp through a 1x12 EVM. IT was a real feat squeezing all of that into the tiny chassis. I used a can cap in place fo the tube rectifier, the standard Princeton filters for the remaining filters and put the relays on the board. That's a tiny little board with not much room on either side.

I hope that works out for you, I love this little amp.