Ceriatone Forum

Ceriatone => Overtone => Topic started by: echidna on March 07, 2010, 10:40:32 PM



Title: OTS S&M
Post by: echidna on March 07, 2010, 10:40:32 PM
Just made an Overtone S&M. Clean channel is great, OD is nasty, woofly, farty, a terrible sound. Any ideas on what it could be.


Title: Re: OTS S&M
Post by: erwin_ve on March 08, 2010, 08:13:44 AM
First of all; get your grid, cathode and plate wires away from the heater wires. It kills sound.
If you don't have a kleinulator/dumbleator/c-lator you could try upping the snubber caps(cer. caps on v2a/v2b)


Title: Re: OTS S&M
Post by: echidna on March 08, 2010, 08:19:45 AM
Do you mean in the way they are resting near each other in the amp, or possible cross connection (shorts) on he tubes?


Title: Re: OTS S&M
Post by: erwin_ve on March 08, 2010, 08:55:17 AM
Do you mean in the way they are resting near each other in the amp, or possible cross connection (shorts) on he tubes?
About the grid, cathode and plate wires vs heater wires; there should be at least 1 cm between the heater wires and the other mentioned.
Snubbers; I mean raising their value(that's what I meant with upping, sorry :P); S&M is stock 270pF. Normal OTS is 330pF


Title: Re: OTS S&M
Post by: echidna on March 08, 2010, 09:02:56 AM
Thanks, i will get in there and have a look at the heater wire distances.
What do the snubbers do then? i do have 330pF spares if they would be a better choice?


Title: Re: OTS S&M
Post by: erwin_ve on March 08, 2010, 09:17:38 AM
Thanks, i will get in there and have a look at the heater wire distances.
What do the snubbers do then? i do have 330pF spares if they would be a better choice?
Snubbers send some of the highs to ground making your sound a bit smoother.
Some people like to make their snubber on v2b bigger than v2A.


Title: Re: OTS S&M
Post by: echidna on March 08, 2010, 09:25:20 AM
Appreciate your help. I think i'll try that today, but first look at wire proximity and maybe change valves.


Title: Re: OTS S&M
Post by: erwin_ve on March 08, 2010, 09:31:40 AM
Appreciate your help. I think i'll try that today, but first look at wire proximity and maybe change valves.
You're welcome. Yes change tubes first! Most problems in tube amps are tubes ;D


Title: Re: OTS S&M
Post by: hywelg on March 08, 2010, 09:31:14 PM

He says it'd take away some of the highs and makes the tone more dumbley.
Has anyone else done this mod (increasing the value on v2b only)? I'd be interested in doing that for my S&M Special and I wonder how dramatic the change in tone will be.

I did the mods to v2 that Pickmaster posted about a year ago. That involved an On-On-On DPDT switch to change between three different values for the v2b snubbers. Well worth doing. FWIW I think I have mine on the highest setting of about 800pF but don't quote me on this my memory might be on the blink. Search Pickmasters posts to find his modded layout.