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AUDIO FORUMS >> D.I.Y. >> CCE Mod on a triode connected EF86
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Message started by fabian on 07/24/11 at 03:13:21

Title: CCE Mod on a triode connected EF86
Post by fabian on 07/24/11 at 03:13:21

Hi,
I am planning on building an ef86 + el84/sv83 tube amp. The ouput socked will be wired with the CCE mod. However, being the ef86 a pentode and not being g3 and k internally connected I was wondering if :
1- Is it possible to apply the cce mod to a triode strapped ef86
2- If so, which would be the value for the cap. would 0.1uF as with the sv83 be just fine ?

Thanks.

Title: Re: CCE Mod on a triode connected EF86
Post by veryoldcat on 07/24/11 at 04:04:36

Hi Fabian,

I posted a very similar question last year (don't remember if it was here, but I think so), but with no answer.

Let's hope for some interest, as I've also been wondering the same thing.

Cheers,
Karl

Title: Re: CCE Mod on a triode connected EF86
Post by fabian on 07/24/11 at 20:44:23

Yep, I saw your post. Before asking I searched the forum to see if the answer was already here but as you said, noone answered :-(

I would try myself and see if it works but the problem is that I´m in Argentina and I want Mundorfs for my amp. The problem is that there is only one Mundorf reseller in Argentina and every time I make a request it can´t be just a couple of caps and I have to wait like forever for them to get here. Besides, costing them aroun 38 euro each, I just can´t afford getting them to see "what happens" and I can´t use another cap and if it works then ask for the Mundorfs because I cannot make a just two caps request :-(

Anybody can help ? There is two of us now. Please :-D

Title: Re: CCE Mod on a triode connected EF86
Post by dank on 07/24/11 at 23:40:23

Fabian, Veryoldcat

Sure. The Zen and Zkit1 are pentodes running in triode mode that use the CCE mod, and the Taboo is a pentode running in pentode mode that uses the CCE mod too. I've never seen anything other than 0.1uf 400v suggested.

Dan

Title: Re: CCE Mod on a triode connected EF86
Post by fabian on 07/25/11 at 02:59:04

Hi there,

Thanks for your answer, however what I´d like to know is if the mod can be implemented in an ef86. I´m planing to build an ef86/el84 amp and being the ef86 a pentode I wanted to try the CCE mod in the ef86 tube. I've seen the CCE Mod on sv83, el34, etc all are output tubes but I´m not sure if it can be implemented in an input signal tube like the ef86 :-D

Thanks.

Title: Re: CCE Mod on a triode connected EF86
Post by dank on 07/25/11 at 13:25:05

As long as you have a pentode with g3 not internally tied to the cathode, the CCE mod should work. I believe the thoughts are that the CCE mod does something with secondary emission electrons that bounce off the plate, keeping them from being re-attracted to the plate and smearing the image. I would think that this secondary emission would be greatly reduced for an input/amplifier stage as opposed to the output stage due to the larger current flow in the output stage. However, the effect might be amplified if it is at an earlier point, so give it a try.

I would suggest getting a couple inexpensive .1 uf 400v polypropylene capacitors and trying it out. If it appears to do something good you can always upgrade to your expensive Mundorfs later.

Dan

Title: Re: CCE Mod on a triode connected EF86
Post by fabian on 07/25/11 at 23:04:01

Hi there, thank you very much for your help. I´ll do that. Once I get the rest of the materials I need for my amp (power trans, chokes, etc etc etc) I´ll implement the mod on the ef86 and will come back with the results.