| Author | Message | ||
| Onion |
There were two versions of the Musicman 210-65 combo - one has a 12AX7A in the preamp and the other is all transistor pre-amp. I have the latter. Is it possible or worth the effort of having it converted to 12AX7A? Also, it it easy to get a bit more top from the amp or would it be simpler to use an external EQ? | ||
| the real onions |
thanks for posting my question Onion! I just wanted to add:- I have a transistional 210-65 with el34's and the 12ax7a blanked off. I'm interested in seeing if a couple of mods are feasible / practical. Regarding getting a bit more treble; there is a post here saying that MM did a modification for Clapton to give him more top. Is it possible to get a copy of the circuit modification so I can take it to an expert here (in Montreal) and get the mod done -I'm loathe to have it butchered by some overconfident nincumpoop so having the actual diagram would give me a bit more confidence. There is also a post here about reverting to the 12ax7a but the outcome isn't clear. I know the two versions sound different -I've played with the older type and to my ears it's more 'fender-y' but would the mod be easier to do? lastly I read that Clapton had the bias turned up full. Could anyone humour this newbie and explain what that means and what the likley effects that would have on A) the sound and B) the longevity of the components. Best wishes, The Real Onions | ||
| The Surrogate Onion |
You're welcome- Don't give another thought to the mentally ill characters elsewhere. There's some seriously sick cases there. This site is excellent and the guys using it are 100% helpful and positive. Steve Kennedy doesn't check this daily. Sometimes a response can take up to a week (or more) but it'll be intelligent, informative and helpful. Best of luck. Regards, The Surrogate Onion | ||
| les vrais oignons |
Thanks for the friendly welcome, it's relief to be away from the warzone that is alt.guitar.amps -I felt like the character in Sleeping Beauty who forgot to invite the bad fairy. cheers - les vrais oignons | ||
| michael kaus |
I have the schematic that the guys at MM hand altered to show what they did to Claptons circuit. It show mod for more treble and for more distortion. I doubt if he cranked up the bias draw as they had enough trouble getting them to stop smoking tubes as it was. I also converted one back to 12ax7 from SS driver but never got toally done as I stupidly dropped a pair of pliars in it while hot-NOT GOOD. Speaking from the experience though, it was a lot of work and it did sound good when done but not worth the trouble. Got some good pictures of the driver board out of ot though if you are inclined to try. I can describe the alterations for treble and dist if you wish-can't find the scan I had of schematic though. Mike. | ||
| onions |
Thanks for your reply,from what you say, I think I won't do the 12ax7 mod at the moment, but I am interested in the treble mod. Given that I know precious little about the insides of amps, could you explain the treble mod in sufficient detail that i could easily pass it on to a local tech? Best wishes - O | ||
| michael Kaus |
I'll be glad to send you the scan of the schematic if you want. Just email me and I'll send it to you. I don't send anything without someone wanting it. Mike | ||
| onions |
'you've got mail' cheers - onions | ||
| Steve Kennedy |
The 12AX7 phase splitter does sound a bit warmer than the solid-state circuit. However, in the right circumstances it is more prone to catastrophic outout section failure and from what I have heard can take out an output transformer if you aren't paying attention. I personally don't think it would be worth going backwards to put the 12AX7 in an amp that doesn't currently have it, but that's just my opinion. If you HAVE a 12AX7 in there, just be prepared to shut the amp down immediately and not attempt to use it if the amp stops making sound suddenly (if the power is still on)! |
Tue, 03/25/2014 - 09:57
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