ODS - any advice?

[Stephen1966]

Greetings tubaholics!

After putting my Tweedle-Dee together earlier this year https://ampgarage.com/forum/viewtopic.php?f=4&t=32962, the time has come to start thinking about the next build and I was mightily impressed by a 12" ODS combo I saw on the internet...

As an update to the Tweedle-Dee, I would like to try Robrobinette's passive effects loop but with the additional Oomph of a rack Dumbleator - which is a "totally necessary" side project I'm working up to as well... The Tweedle-Dee (5E3-D) sounds just great and yet, there are always improvements to be made so I will be posting more on that subject later... (I do like the idea of keeping the active electronics of the FX loop outside the 5E3 chassis - it's already a bit like Tetris in there!)

Anyway, back to the ODS. I've already downloaded a bunch of files and schematics and the later #124 is just a cherry so this is the circuit I would like to build. I had good results with metal film resistors in the 5E3-D circuit and this is an avenue I would like to explore with the ODS as well. I'm not setting out to build a faithful replica, it's a functional amp I want, not so much a museum piece. So there will be an essential bit of experimentation going on. This at least, seems in line with Dumble's philosophy of tailoring the sound to the player (i.e. me). The 124 circuit is just beautiful though and the more I study it, the more I learn...

So the question to all my fellow Dumbleites is, has anyone ever gone down this road before? And if so, what advice do you have? It took months of research and learning to get to grips with the Tweedle-Dee and it still continues to instruct (hence the mods coming soon) but I ask myself, how much easier would this have been if I had had the courage to ask about it from you guys (and any gals) first? So, living and learning, this is me asking...

Stay safe everyone.

Stephen

[martin manning]

So the question to all my fellow Dumbleites is, has anyone ever gone down this road before? And if so, what advice do you have? It took months of research and learning to get to grips with the Tweedle-Dee and it still continues to instruct (hence the mods coming soon) but I ask myself, how much easier would this have been if I had had the courage to ask about it from you guys (and any gals) first? So, living and learning, this is me asking...

That's actually a pretty well-worn path. Looking at your Tweedle thread, I see you can fabricate the boards (I'd go with eyelets rather than turrets), and there are full scale templates to work from here on the site. Find a suitable chassis and you are on your way. I would start with the circuit as drawn, except for the odd 345k OD entrance trimmer (use 100k). New components are perfectly fine, as proven in many examples. Just use good quality parts, and stay with polyester caps. The original used MF resistors in selected locations, IMO for low noise and precision, but there's no reason you can't use them everywhere else.

[Stephen1966]

Eyelets yes! The turrets seemed a good idea at the time, but it would have been easier fitting everything inside the compact chassis with eyelets. Now I've lived with it for a few months, I don't see much (if any) mechanical advantage to turrets unless we are going to start going all Vox and chucking cabinets down stairs.

I haven't seen the templates yet, unless you mean the layouts - in any case, I will probably go the TD route and tailor the boards to the components and signal path. It's early yet, but I imagine that's all pretty well figured-out by now.

Thanks Martin, I'll heed the caps and resistors advice.

[didit]

Hello -

See ODS eyelet board layouts. Print, confirm dimensions came out properly and then drill baby drill.

Best .. Ian

[Stephen1966]

Thank you Ian. That's great. PCB's as well... I can make those but I think eyelet boards are the route I would take.

Martin, you're a genius!

(You see, Stephen! It is better to ask first.)

Stephen

[Stephen1966]

Late last night I was watching Andy Fuchs describing the evolution of his amps and he said something which gave me food for thought... I'll paraphrase because I can't remember exactly what he said, but it was something along the lines of 'the Dumble ODS seemed like a work in progress'. I don't know if we can say that's true, but as a tinkerer myself, it did get me thinking.

I'm very interested in what you think. Are there improvements that could be made? Has anyone made any changes either to the circuit or by adding functions that worked out especially well?

I seriously need to think about solid state rectification, about pentode/triode switching, about on-board FX loops and yeh, reverb. Reverb sounds good...

[Lothy]

Hi Stephen,

I've done an ODS 8 months ago. It was a real challange for me, because it was my first amp ever. Took me almost 6 month of research before I heat up the iron.
I have collected all necessary and unnecessary things in a drop box folder. Hopefully it makes things easier for you:

https://www.dropbox.com/sh/qdrx07ww90pp ... 0qDOa?dl=0

You can find almost everything here, but it is streched over multiple threads.

I went for the #124 circuit and used common and highly available parts, nothing special, or mojo. Go for good quality in components but do not pay for silver bullets. For example I used F&T electrolytics & Dale resistors only in the signal path. Standard Twin-Reverb iron does the job. After cleaning up my wiring mess, it turns out to be the amp of my life. Or until I build a better one . I can hear a whisper in me saying ... SSS. Might be a snake......

Just to mention, I really appreciate the support from the members of this forum. No tube-amp-builder-elite-snob-dickheads here, like I found in other forums.

Cheers
Gerhard

[j0k3335]

Hi Stephen,

...

Just to mention, I really appreciate the support from the members of this forum. No tube-amp-builder-elite-snob-dickheads here, like I found in other forums.

Cheers
Gerhard

... and I appreciate all your informations

Thanks a lot

[Stephen1966]

Lothy, thank you. That is really helpful... both the necessary and the unnecessary! My first amp was the Tweedle Dee and you're right about the research. Building the thing takes no time, but figuring it all out beforehand, that takes ages. This info you provide is like jumping to light speed. Brilliant, I can't thank you enough.

I also just want to echo your sentiments about the civility of the guys in this forum. This was how the internet was supposed to be.

[Synchu]

I wouldn't exactly describe the ODS as a work in progress, but you can definitely see how it developed through the years - some like the developments, some not. The thing that I always had in mind, is that these amps are supposed to be tweaked and refined - the man himself does this to each build.
I have more than a few and just finished a second gen hybrid. While this is the least tweaked of the herd (yet - not sure it'll stay that way), it does sound great in its own way, despite being one of the earlier designs.
Since once you started riding the wave, you'll inevitably build more and my advice (FWIW) will be to pick one that is closest to your current desires and go for it. Should you feel you have to get an exact tone (Ford, Carlton, etc.) and go chasing specific parts - then do so as well
My current understanding for all amps I build is - start with something inspiring and tweak it later, you can get a usable guitar amp with pretty much nothing as parts count and quality (yeah - that's how lo fi are our beloved tools of trade).

SSS is a great amp - very different from ODS - easily my favorite one and definitely most unique - you can't duplicate it - I laugh anytime I read an ad selling a pedal that does "the SSS". So glad I took the plunge some years ago and so grateful to mhartman - the forum member, who did the initial layout and undertook the hefty research. Now, with the two forum members that cover Americas and Europe - supplying chassis and readily made PCBs, I think it's kinda no-brainer whether you should do it or not

Niki

[martin manning]

... I think eyelet boards are the route I would take.

I've posted some new eyelet board layouts using radial caps. Same location as the traditional eyelet boards.

[talbany]

Late last night I was watching Andy Fuchs describing the evolution of his amps and he said something which gave me food for thought... I'll paraphrase because I can't remember exactly what he said, but it was something along the lines of 'the Dumble ODS seemed like a work in progress'. I don't know if we can say that's true, but as a tinkerer myself, it did get me thinking.

I'm very interested in what you think. Are there improvements that could be made? Has anyone made any changes either to the circuit or by adding functions that worked out especially well?

I seriously need to think about solid state rectification, about pentode/triode switching, about on-board FX loops and yeh, reverb. Reverb sounds good...

So here is my .02 cents on this. Having been through the whole Dumble evolution as well as one of the original members here and watched and read so many other builders (Commercial and DIY'ers) over the years comment and struggle through certain aspects of the design tweaking their way to what they think is the "perfect amp" and most having never even played a real ODS and all the while tweaking their way further from the sound of the original 102 or a 183 or a whatever ODS design they grabbed from the files section.. Having been in the "commercial" end the pressure then becomes to add more options?. Reverb/Built in loops/ and other mods and tweaks that the general public perceives as a more flexible/Marketable/ user friendly amp all the while straying further away from the sound of the original design. Many of these builders will get around this by saying "I have my own sound" I am after.(Ya Think!)

Having played through I don't know how many ODS clones/copies (whatever you want to call them) There has only been a handful that I can think of that I've come away thinking this sounds like the real deal and most sounded good and were more versatile yet at the same time remind me nothing of the performance and sonic aspects of say a 102 or a 183,which is what got me interested in the whole Dumble thing to begin with..
If your goal is to then use the layouts and designs on this site to just come up with a proven design that works and form your own sound? this design is certainly a wonderful platform to use as a springboard to mod away,(As did Andy) just know that the more you mod the more likelihood you "will" run into problems with how the amp performs (especially with respect to the overdrive side and or overall balance of the amp) sending you down another rabbit hole of potential bandaids if things don't go as planned?.

BTW..If your asking if you or others will like a particular mod or design change?.. How should I know. I've never even heard you play

The details add up quick!

Good Luck!

Tony

[rootz]

I’m with Tony on this one and add to that: most of us never heard let alone played a real Dumble. You would actually have to do a double blind test to hear how close you are to the real deal.

In the past year I’ve build two ods based amps, but with reverb. One is based on #94 the other on #124. They are no clones! Do they come close to the originals? No idea! I do hear some characteristics I hear on recordings with Dumbles though. They make for some fine instruments anyway. Big, bold, expressive, dynamic like I’ve never heard before. The #124 has got that great snarl to if, the #94 is a bit more polished.

For me it’s not that relevant to come super close to the original builds and sounds. I like tinkering, creating something of my own, finetuning and ended up with two amps that I genuinely like in the process. I do always use quality components though: 6ps caps, Draloric, Roedersetin, Nte or Koa resistors, Cts and Alpha pots, etc. I could improve further in many areas though. Those are the details that add up.

So if you want a #124, start sourcing parts. Jelle Welagen sells j-taper 1 Meg CTS pots and complete sets of resistors for a #124. Don’t know what he asks for them these days. Find yourself some nice vintage iron from a Fender Twin. NOS tubes help too.

[norburybrook]

I've built quite a few ODS amps over the past few years and started by building exactly as specified. I then started tinkering .......everytime I started to tinker I always came back to a specific build in the end.


The only 'tweaks' I now do different to the originals is having the FET on a relay and the gain pot in the FET jack input and sometimes having LNFB on a switch on models that didn't have it originally, like the Bluesmaster for example.


main thing is to be safe and have fun building and then enjoy the fruits of your labour.


M


p.s. you will need to have a dumbleator at some point too if you're using the FX loop and the OD on the amp. It also adds another set of variables to your tone too

[talbany]

I’m with Tony on this one and add to that: most of us never heard let alone played a real Dumble. You would actually have to do a double blind test to hear how close you are to the real deal.

In the past year I’ve build two ods based amps, but with reverb. One is based on #94 the other on #124. They are no clones! Do they come close to the originals? No idea! I do hear some characteristics I hear on recordings with Dumbles though. They make for some fine instruments anyway. Big, bold, expressive, dynamic like I’ve never heard before. The #124 has got that great snarl to if, the #94 is a bit more polished.

For me it’s not that relevant to come super close to the original builds and sounds. I like tinkering, creating something of my own, finetuning and ended up with two amps that I genuinely like in the process. I do always use quality components though: 6ps caps, Draloric, Roedersetin, Nte or Koa resistors, Cts and Alpha pots, etc. I could improve further in many areas though. Those are the details that add up.

So if you want a #124, start sourcing parts. Jelle Welagen sells j-taper 1 Meg CTS pots and complete sets of resistors for a #124. Don’t know what he asks for them these days. Find yourself some nice vintage iron from a Fender Twin. NOS tubes help too.

I agree!
The ODS is already a bitch of a build to get both clean and OD channels completely transparent and well balanced and not have something about the amp that bothers you. IMO if you use the right parts and build correctly the design is capable of sounding great with just about any amp setting,guitar,tube choice, Speaker selection and with or without the Dumbleator attached.. No mods or tweaks required..


"Can you add reverb to my 5F6A Bassman"
Sure but it will no longer be a 5F6A Bassman!
Tony