ODRS build log
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				rootz
- Posts: 721
- Joined: Sat Jan 03, 2009 12:24 pm
- Location: Delft, The Netherlands
        
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		ODRS build log
No, not a #13 or #60 or any existing ODRS. This is going to be a high plate classic with reverb, much like the CRS v3 like amp I did last time. Major difference is that this amp will sport Peavey Deuce transformers, which were recommended by Norburybrook and Erwin.
The design is a bit different from the crs v3. Reverb is taken directly from the clean/od relay. Driver is an 12at7. Mixing is done with a tweed mixer, but the non reverb side set up at just a gain of 6 dB. Not really an idea what to expect sound wise, other that it leans to the 94 preamp wise. That one was owned by Grogor Hilden and I loved the sounds he got out of it with a strat and a Paul.
Anyway, pictures tell more than a 1000 words, so here we go.
First some mock ups.
			
			
						The design is a bit different from the crs v3. Reverb is taken directly from the clean/od relay. Driver is an 12at7. Mixing is done with a tweed mixer, but the non reverb side set up at just a gain of 6 dB. Not really an idea what to expect sound wise, other that it leans to the 94 preamp wise. That one was owned by Grogor Hilden and I loved the sounds he got out of it with a strat and a Paul.
Anyway, pictures tell more than a 1000 words, so here we go.
First some mock ups.
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						Re: ODRS build log
Then some of the boards. Need to do bias and relay supply, as well as the Fet board next.
			
			
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						Re: ODRS build log
Some test fitting and exterior shots.
			
			
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						- dorrisant
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Re: ODRS build log
Nice. Where did you get your boards?
			
			
									
									"Education is what you're left with after you have forgotten what you have learned" - Enzo
						- norburybrook
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Re: ODRS build log
fantastic Rootz  are you going with FWB rectifier to give around 500V  on the plates
 are you going with FWB rectifier to give around 500V  on the plates  
 
Looking a million dollars already
M
			
			
									
									
						 are you going with FWB rectifier to give around 500V  on the plates
 are you going with FWB rectifier to give around 500V  on the plates  
 Looking a million dollars already

M
Re: ODRS build log
That black "suit"... mmhhh, lovely!
TT chassis?
I don't see the point in having two plugs pre-cut on blank chassis... 
 
I think I'd rivet a (stamped) plate on the unused cut, if I were to use one of these.
			
			
									
									
						TT chassis?
I don't see the point in having two plugs pre-cut on blank chassis...
 
 I think I'd rivet a (stamped) plate on the unused cut, if I were to use one of these.
Re: ODRS build log
Wow, very nice work.  Looks great!  Good looking transformers too.
			
			
									
									
						Re: ODRS build log
Yeah, tt chassis. Those come with pre cut holes. The extra inlet will be welded so it is permanently closed. Might get covered by a back plate anyway. Totally get your point about one of them being redundant.
What I truly don’t like about the chassis is the pre cut holes for the cage nuts. Those will never fit with the chrome corners. Second time I have to make 4 new ones. For a small amp the structural strength is good enough with these extra holes, but for this one I’m thinking about filling them and welding the corners of the chassis. Both can be done in a friends workshop.
Big plus of the tt chassis: just 20 euros! Cheaper than custom made (done that before). If I were to make more chassis, I’d make a drawing in inventor and order in multiples of 10 or 20.
Thanks for the compliments about the suit! Home made with basic tools, some experience and patience.
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				rootz
- Posts: 721
- Joined: Sat Jan 03, 2009 12:24 pm
- Location: Delft, The Netherlands
        
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		Re: ODRS build log
Those boards are home made! Simple toner transfer method. I’ve done custom boards before, from China, the US, Belgium. Always top notch but also not fast or expensive. I think those home made boards are very much in the spirit of HAD. Most of his boards I have seen on pictures look hand made, might even be done with a sharpy to make the traces. Anyway, this method suits me well and makes room for lots of experimenting.
Re: ODRS build log
Thanks Marcus! I hope those trannies are still ok. One of the tubes in the amp had a broken guidance pin. I noticed when one of the tubes red plated!!! Transformers test ok by the way, so I think I’m safe. Otherwise I need yet another Deucenorburybrook wrote: ↑Tue Jun 09, 2020 5:20 pm fantastic Rootzare you going with FWB rectifier to give around 500V on the plates

Looking a million dollars already
M
Indeed standard bridge rectifier. 480 V at least on the plates. I upped the first resistor in the dropping string to 4.3k ohms, hoping it will land V1 on 190V or so. I’ve got a whole array of resistors to test with, ranging from 2k2 to 2k7. Let’s hope 4k3 is just right and saves me some work.
Re: ODRS build log
Thanks mate! Those transformers are huge!! Standing Pt should get rid of any possible problems with the reverb. The reverb transducers are oriented in another direction IIRC.
There was one gamble I didn’t wanna take: van the pt supply 5 extra preamp tubes. So I ordered a small transformer which now is where the relay transformer would normally be. It’s a 6.3-0-6.3 12.6 VA transformer. Cheap, hopefully does the trick and the Peavey transformer will be safe like it has been for 40 years.
Re: ODRS build log
Nice Bas, you did a fantastic job and preparation already. Love to hear the outcome IRL. 
			
			
									
									
						
- dorrisant
- Posts: 2790
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Re: ODRS build log
No worries... They look good. I thought you might have bought them somewhere, that's all.rootz wrote: ↑Tue Jun 09, 2020 6:21 pmThose boards are home made! Simple toner transfer method. I’ve done custom boards before, from China, the US, Belgium. Always top notch but also not fast or expensive. I think those home made boards are very much in the spirit of HAD. Most of his boards I have seen on pictures look hand made, might even be done with a sharpy to make the traces. Anyway, this method suits me well and makes room for lots of experimenting.

"Education is what you're left with after you have forgotten what you have learned" - Enzo
						Re: ODRS build log
Oh no problem Rafael (IIRC) I wasn’t feeling attacked or something. I was actually a bit proud you thought I had them made somewhere while I did make them using such an unsophisticated method. So to recap, no worries from my side and hopefully not from your side either.dorrisant wrote: ↑Tue Jun 09, 2020 6:58 pmNo worries... They look good. I thought you might have bought them somewhere, that's all.rootz wrote: ↑Tue Jun 09, 2020 6:21 pmThose boards are home made! Simple toner transfer method. I’ve done custom boards before, from China, the US, Belgium. Always top notch but also not fast or expensive. I think those home made boards are very much in the spirit of HAD. Most of his boards I have seen on pictures look hand made, might even be done with a sharpy to make the traces. Anyway, this method suits me well and makes room for lots of experimenting.
Re: ODRS build log
Thanks Erwin! It’s actually pretty much all preparation and some assembly lol. So many hours drawing, comparing, investigating, etc.
One thing I haven’t worked out completely. I would like to use 0,5mm2 solid core hookup wire through the amp. Looks like Dumble did that too, at least around the main/preamp board. Really the only supplier I could find is TT in Germany. It says 900V on the website, but insulation is really thin, so I doubt that. All other high voltage cable I could find like Liv-y is stranded, or sold per spool thus expensive. Any ideas/what do you use?
I’m also looking for a nte fet (452?) or 2n4416 (equivalent?). You happen to have any? Maybe we should exchange cell phone numbers, when finished id like to show you this new beast in real life



