Concert II Discussion

proaudioguy · Post by **proaudioguy** » Mon Aug 27, 2012 7:51 am

I hqve been lurking for a while now. Really like this site.
I have some ideas I want to bounce off you folks.
The 80s Concert seems like te perfect amp to start with (if you aren't building from scratch). How would you go about laying it out? How about a non hrm in place of the old lead channel using pull pots for the switches and a straight up BF (or whatever you like) in place o the current clean channel? The amp has 7 preamp tubes. V1 could be the bf. v2-v3 the Dumble (hrm or not). V4-v5 reverb, 6 dumblator, and v7 the PI. Even then there is still half a tube unused.
Any suggestions on where to start with this amp, what to keep etc?

Where can I purchase relays. I think the vactrols need to go away regardless?

Are there any layouts using the existing concert II eyelet board?

Those that have used it, what are your thoughts on the JBL K120? I'm very familiar with EV. Not so much JBL.

Darkbluemurder · Post by **Darkbluemurder** » Mon Aug 27, 2012 8:16 am

That's pretty much how I had set up mine for a while - clean channel AB763 and lead channel ODS non HRM. I tried to get around using the existing layout but this is far from optimum IMHO. I have later converted by Bassman head with one of the suggested layouts here in this forum and the amp sounded much better to me.

The transformers are OK to use.

Cheers Stephan

Mark · Post by **Mark** » Mon Aug 27, 2012 10:15 am

The stock lead channel is pretty ordinary, and there is the extra triode. It would seem to be the ideal platform. I wish I knew this when I owned a Concert II.

I believe there are a whole lot of mods around for these amps too. Again, I wish I knew this when I owned a Concert II.

proaudioguy · Post by **proaudioguy** » Mon Aug 27, 2012 11:51 am

What I'm suggesting is actually 3 channels. Ab763 and Dumble. There are enough knobs and tubes to make the lead channel into the Dumble clean and OD leaving the vol bass treble for the old clean available to do the ab763 deluxe reverb preamp. Channel switching with relays would be easy. Is it too much? I kind of like te idea of going from crystal clean ab763 to clean Dumble with pab on for some grit and to OD for leads. It's just an idea.

FUCHSAUDIO · Post by **FUCHSAUDIO** » Tue Aug 28, 2012 1:54 am

The Fender 75 is equally good for D-clone building.

proaudioguy · Post by **proaudioguy** » Tue Aug 28, 2012 2:15 am

FUCHSAUDIO wrote:The Fender 75 is equally good for D-clone building.

Glad to know they are good for something. I'll keep my eyes open cause those go pretty cheap.

I'd love your take one what I'm considering (and your layouts

.

alvarezh · Post by **alvarezh** » Tue Aug 28, 2012 2:47 am

Andy's layouts? Oh boy, they could be patented!

Google Fuchs Audio Technology, see what you come up with!

BTW, welcome to the forum!

FUCHSAUDIO · Post by **FUCHSAUDIO** » Tue Aug 28, 2012 2:23 pm

Appreciate the welcome, except I've been here for over ten years...lol.

Thanks for the kind words!

proaudioguy · Post by **proaudioguy** » Tue Aug 28, 2012 2:31 pm

I thought he was welcoming me.

VacuumVoodoo · Post by **VacuumVoodoo** » Tue Aug 28, 2012 2:43 pm

This site is about sharing so take it as a shared welcome

alvarezh · Post by **alvarezh** » Tue Aug 28, 2012 3:17 pm

"I thought he was welcoming me."

Absolutely! you have 5 posts, Andy is a very old dog around here, surprised he didn't catch that.

Cheers!

FUCHSAUDIO · Post by **FUCHSAUDIO** » Tue Aug 28, 2012 3:28 pm

too early in the day, not enough coffee yet.....

proaudioguy · Post by **proaudioguy** » Tue Aug 28, 2012 7:51 pm

Thanks for the welcome.

SO here's a twist. I powered up the amp (first time for me) and the clean channel sounds terrible while I like the dirty channel. It's kind of like my superchamp lead (slightly modded) but smoother and fuller and with reverb. OTOH My SC clean blows this away (only mod to the SC clean is smaller snubbers). My AB763 (turret board) 1968 Twin Reverb loaded with a pair of EVs is my reference for clean. The SC plugged into the Concert's speaker is very close. The Concert's clean is very very dark. I'll look into it when I have some down time.

There is a .001 Snubber on V1 in the schematic but nothing on V2B (after the tone stack). I'm afraid if the V1 Snubber is responsible for the dark sound of the clean, it's also helping the lead channel, which is also dark when set clean, but really nice when the gains are dimed. If I fix the clean, it's going to fix the lead at lower gain settings but make the lead too bright at higher gain settings. Hmm.....

vibratoking · Post by **vibratoking** » Tue Aug 28, 2012 8:26 pm

I owned a Concert II for many years and just recently sold it. The cleans are very good in that amp. Mine was stock FWIW. It was a 1x12 combo with the blue label speaker. I don't remember the brand, but that speaker sucked big time. Flabbiest fartiest thing I've ever heard, but hat doesn't sound like your problem since you plugged your SC into it.

Also, the magic with that amp occurs when you jumper the loop send/return and use the extra tube stage to tweak the gain structure. With the loop, it has a very good sound on both channels and I never felt the need to mod it.

proaudioguy · Post by **proaudioguy** » Tue Aug 28, 2012 10:16 pm

vibratoking wrote:I owned a Concert II for many years and just recently sold it. The cleans are very good in that amp. Mine was stock FWIW. It was a 1x12 combo with the blue label speaker. I don't remember the brand, but that speaker sucked big time. Flabbiest fartiest thing I've ever heard, but hat doesn't sound like your problem since you plugged your SC into it.

Also, the magic with that amp occurs when you jumper the loop send/return and use the extra tube stage to tweak the gain structure. With the loop, it has a very good sound on both channels and I never felt the need to mod it.

The previous (original) owner put in a JBL K-120. I am very impressed with this speaker. It's not the cause of the dark tone.

The clean sounds like my twin with a blanket over it. Now I understand what people mean when they say that. They mean it quite literally. I have a feeling it's the V1 Snubber.

Maybe I should remove the Snubber altogether and try to tailor the HF roll off on the lead channel another way. Maybe an adjustable way (guitar tone knob comes to mind but I hate twiddling with it) This might be better because at lower more blues oriented gain the lead channel is too dark too. I noticed I like the presence up about 4 on the lead channel with both gains dimed so I may have to take the presence down. It will take me longer to remove the chassis than to clip one lead on that snubber.

The guys that are moving the tone stack to the end, what is that doing to the tone besides giving you a lot more distortion? Lets say you set the distortion to about the same, albeit a lower number on the dial.

I just spent half an hour playing my Super Champ through the K-120 and It sounds so good I'm going to look for the 10" version and try it out in the SC. The speaker is my main issue with that amp, along with the JJ 6V6S tubes hissing with certain notes. Not a problem when plugging into the other cabinet.

I'll jumper the FX loop next time I get a chance to crank it up. Wifey isn't really enthusiastic about my hobby and she's due home soon.

The Amp Garage

Concert II Discussion

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