Getting a smoother OD
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- ijedouglas
- Posts: 776
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- Location: Southern California
Re: Getting a smoother OD
If you are happy with your cleans, I would give it time to break in and then re-evaluate your OD.
What are your plate voltages?
If it is still too harsh I would concentrate on components around V2 as well as the OD trimmer.
I would also recommend changing one thing at a time and re-evaluating whether you are closer or further from your goal.
Things to try:
- 68K 1 watt Piher Carbon Film grid stopper on V2a (you can find these on ebay)
- Carbon film 180K on V2b
What are your plate voltages?
If it is still too harsh I would concentrate on components around V2 as well as the OD trimmer.
I would also recommend changing one thing at a time and re-evaluating whether you are closer or further from your goal.
Things to try:
- 68K 1 watt Piher Carbon Film grid stopper on V2a (you can find these on ebay)
- Carbon film 180K on V2b
Ian
Re: Getting a smoother OD
Was just looking at your snubbers on V2
They look like they are wired between pins 2 and 3 and
pins 6 and 7
should be 1 and 3
6 and 8
They look like they are wired between pins 2 and 3 and
pins 6 and 7
should be 1 and 3
6 and 8
Re: Getting a smoother OD
Here is a voltage chart. First time for this, hopefully its accurate
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Phil
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Charlie Wilson
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Re: Getting a smoother OD
The Dales on the grids would not be my first choice and the metal films on the LNFB either.
CW
CW
Re: Getting a smoother OD
Here is the voltage chart as a jpg...
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Phil
Re: Getting a smoother OD
Heard that from Ian as well, I'll look into replacing. Suggestion for brand and sources?Charlie Wilson wrote: ↑Thu Dec 24, 2020 11:28 pm The Dales on the grids would not be my first choice and the metal films on the LNFB either.
CW
Phil
Re: Getting a smoother OD
Seriously, wait until its burnt in. And it takes a while unless you have a load box and can let it run continuously. I built my Ceriatone OTS way back in 2008, burn in wasn't really recognised back then and I modded mine to add a stepped hi-cut to the OD circuit. After about a year or so of very intermittent gigging the cut stays on zero or first notch only. I've never got around to removing it. It could easily be an on-off-on toggle sw.
Re: Getting a smoother OD
Just checked, they are 1-3 and 6-8. Probably hard to tell from the first gut shot.
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Phil
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Charlie Wilson
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Re: Getting a smoother OD
Bought a pair of sneakers and they were a little tight, guy at the store said don't worry they'll break in. Ended up with torn seams in the shoes and shin splits. Sorry I had to be a wise guy.philbard wrote: ↑Thu Dec 24, 2020 11:31 pmHeard that from Ian as well, I'll look into replacing. Suggestion for brand and sources?Charlie Wilson wrote: ↑Thu Dec 24, 2020 11:28 pm The Dales on the grids would not be my first choice and the metal films on the LNFB either.
CW
CW
Re: Getting a smoother OD
Thanks Charlie, ordered the 10 megs already and will look for the Xicon's.Charlie Wilson wrote: ↑Thu Dec 24, 2020 11:50 pmBought a pair of sneakers and they were a little tight, guy at the store said don't worry they'll break in. Ended up with torn seams in the shoes and shin splits. Sorry I had to be a wise guy.philbard wrote: ↑Thu Dec 24, 2020 11:31 pmHeard that from Ian as well, I'll look into replacing. Suggestion for brand and sources?Charlie Wilson wrote: ↑Thu Dec 24, 2020 11:28 pm The Dales on the grids would not be my first choice and the metal films on the LNFB either.
CWSure let it break in if you want. Can't hurt. At least not as much as those shoes did. You've got Xicon 1w carbon films everywhere else, so maybe try those on the grids. For 10meg on your LNFB buy these https://www.ebay.com/itm/10-meg-1-4-wat ... 2749.l2649. Tony turned me on to them and they are the only ones I have liked so far in that spot. I bought a few more before I posted this.
![]()
CW
Phil
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Charlie Wilson
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Re: Getting a smoother OD
The Xicons are pretty easy to source. Mouser, Antique Electronics, etc. Don't get 1/2 watt, they don't sound that good. Get 1w. Also, lead dress. Cut that zip tie around your OT leads and get your OD cathode and plate wire away from the secondarys. Dumble likes to run the two cathode wires right next to each other. Sorry, one more thing. Get a 110k and 120k carbon film for your PI plates. My bad, just noticed the tied wires are your loop wires not OT.
CW
CW
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Re: Getting a smoother OD
Thanks for the ordering info, done.Charlie Wilson wrote: ↑Fri Dec 25, 2020 12:10 am The Xicons are pretty easy to source. Mouser, Antique Electronics, etc. Don't get 1/2 watt, they don't sound that good. Get 1w. Also, lead dress. Cut that zip tie around your OT leads and get your OD cathode and plate wire away from the secondarys. Dumble likes to run the two cathode wires right next to each other. Sorry, one more thing. Get a 110k and 120k carbon film for your PI plates. My bad, just noticed the tied wires are your loop wires not OT.![]()
CW
Yeah, threw me off for a moment there on the ties. No worries...
Phil
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Charlie Wilson
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Re: Getting a smoother OD
I'll throw you off a little more.
In the photo you have a mini zip tie on your OT leads and one on your PI input(loop) leads. You may want to get the loops wires away from your OD wires after all. There is a good amount of signal going through those and it could, maybe, dirty up the OD a bit. Study the picture I took of #94. It is a good example of how Dumble typically did his lead dress.
CW
CW
Re: Getting a smoother OD
This is a 50W, so the Bassman transformer would be the usual choice, no?martin manning wrote: ↑Thu Dec 24, 2020 4:51 pmThe standard ODS OT is Fender Twin Reverb/Showman, so you want the equivalent to that. The Heyboer site directs retail customers to buy from Mojo, whose Twin Reverb part number is 775. No one here has heard your amp yet, so we don't know how smooth it is or isn't ;^)
- martin manning
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