2 Variac's clip

[Its Luke]

So here's a quick sample clip. Didn't have time to play with mic placement or try and mix/EQ, etc. I'm trying the amp here at 70VAC. Volume was low. Hardly even loud even at a bedroom level. Amp feels anemic and harder to play but there's something pretty wicked about the tone. Will try a little thump with the MXR 6 band or Micro Amp in front when I have more time. 2nd Variac (between head and cab) set at 90. Just a touch of verb in post.

http://www.soundclick.com/bands/page_so ... D=13186163

Beautiful tone on this James! This is the tone I am hoping to achieve.

I am a student at this with a lot to learn, this is where I am looking to go.

-Apologize that I am a little late to the party here-

Any update to your setup?

[Strat78]

Though James is the first to dial in a JTM45 it's been a real eye opener these last couple years experimenting how the amp is run to get that heretofor mythical tone. We had our variacs dialed to 90v for years thinking that did something to the tone. We were also running a variac between the head and cab which was fun but a work in progress. So Rob and James come along and start dialing knobs where no knob has gone before and then it all happened!
Luke, what is your amp setup now? Are you considering building a plexi clone?

[jnew]

Hey Luke, thanks for the props. The good news is (very good news at that), is that you are in the right place to learn the Plexi circuit, Marshall Amps, etc. Collectively, I think the vast majority here would agree that a stock 68 Plexi circuit is the foundation of it all. I happen to start my journey with a JTM-45 Re-issue as Phil (Strat78) said but it's all been changed to a 68 circuit with only two tubes and an oddball, but effective OPT Transformer. From there it's variac's, voltages, Guitar/PU and speakers. An accurate EP-3 pre-amp circuit is also used in my setup but you'll hear many here killing it without.

As it stands now, my setup is the same. I'm always dinkin around with old PU's that I might find in pawn shops or parts bins from music shops but my favorite is still the setup from the clip so far. I don't do the re-amp thing anymore because this is superior IMO. If it's really late at night and I feel like playing quietly, I just practice through an old little Samick amp that a friend found in a dumpster like 5 years ago. With an old Boss PQ-4, pedal, you can make any amp sound pretty wicked.

Phil, I think dialing a variac to 90VAC, does do something to the tone but really only if the amp is left biased at 110V or 120V. Are you hearing it the same when dropping to 90V? This is interesting to me.

Oh, I aways forget. This amp does still use a GZ-34 tube rectifier, I can swap that in about 5 seconds flat but I just like the way it sounds and feels so I leave it. The OPT Trans and GZ-34 are the only 2 parts in the JTM-45 DNA. All else is 68 era circuit.

[Its Luke]

Though James is the first to dial in a JTM45 it's been a real eye opener these last couple years experimenting how the amp is run to get that heretofor mythical tone. We had our variacs dialed to 90v for years thinking that did something to the tone. We were also running a variac between the head and cab which was fun but a work in progress. So Rob and James come along and start dialing knobs where no knob has gone before and then it all happened!
Luke, what is your amp setup now? Are you considering building a plexi clone?

Thanks for the response Phil

I currently have a Marshall JMP-1 watt head and have a 1x12 cab with a scumback pvc greenback clone and the other 1x12 has a scumback blackback clone speaker. My other amp is a 74/74 Ampeg VT 40, which is a 60 watt amp in a 4x10 combo.

Was thinking of either building a 12 series style clone, or to have George build something for me. I am just a home player at this time with a busy schedule between work and kids, however I would like to play out a few years down the line when time permits and my chops get to where they need to be.

I just picked up an original 74 phase 90, and a 76 MXR 6 band EQ, and already have a mid 70's EP3 echoplex.

Current guitar lineup is a vintage 50's Les Paul with PAF's and a Tele, so I will be looking for an ash body strat soon as well.

[Its Luke]

Hey Luke, thanks for the props. The good news is (very good news at that), is that you are in the right place to learn the Plexi circuit, Marshall Amps, etc. Collectively, I think the vast majority here would agree that a stock 68 Plexi circuit is the foundation of it all. I happen to start my journey with a JTM-45 Re-issue as Phil (Strat78) said but it's all been changed to a 68 circuit with only two tubes and an oddball, but effective OPT Transformer. From there it's variac's, voltages, Guitar/PU and speakers. An accurate EP-3 pre-amp circuit is also used in my setup but you'll hear many here killing it without.

As it stands now, my setup is the same. I'm always dinkin around with old PU's that I might find in pawn shops or parts bins from music shops but my favorite is still the setup from the clip so far. I don't do the re-amp thing anymore because this is superior IMO. If it's really late at night and I feel like playing quietly, I just practice through an old little Samick amp that a friend found in a dumpster like 5 years ago. With an old Boss PQ-4, pedal, you can make any amp sound pretty wicked.

Phil, I think dialing a variac to 90VAC, does do something to the tone but really only if the amp is left biased at 110V or 120V. Are you hearing it the same when dropping to 90V? This is interesting to me.



Oh, I aways forget. This amp does still use a GZ-34 tube rectifier, I can swap that in about 5 seconds flat but I just like the way it sounds and feels so I leave it. The OPT Trans and GZ-34 are the only 2 parts in the JTM-45 DNA. All else is 68 era circuit.

Thanks James, I feel like I have landed in the right spot in this forum! Incredible wealth of experience and knowledge here, I am just a newbie here and trying to soak up as much as I can as I start the journey.
Blown away by your clips with the 2 variacs, puts a huge smile on my face. Hopefully with some time, a little luck and some help from you guys I will get there. Can't thank you enough for the feedback so far.

[jnew]

It's all good. Not likely any question you ever have, will go unanswered and that smile will be from your gear singing.

[Mats A]

Excuse me for being stupid but how do you hook this up? Is there a second Variac placed between the amp and cab? How does that work? How do you connect it?
Thanks!

[Mr.Farva]

Excuse me for being stupid but how do you hook this up? Is there a second Variac placed between the amp and cab? How does that work? How do you connect it?
Thanks!

Set the wall variac to 110-0 volts and the cab variac at 90

[jnew]

Yep, this diagram shows it. However, unless you have a variac with binding post's, like the red one shown in the diagram, you will have to adapt the AC electrical cord normally plugged into the wall, to a 1/4 inch speaker jack for the back of the head. And likewise for the AC plug out of the variac, adapted to a 1/4 inch speaker plug into the cab. All of which, very very easy though.

[Mats A]

THANKS!
Do you then lower the Variac from the wall socket? I mean 110 isn´t that what you´ve got in the US? I mean if you have it at 110 why the need for a Variac? I got 230V here in Europe Sweden. Does the Variac between the amp and cab become like an attenuator? Could you use an attenuator instead?

[Strat78]

I think the most important thing here is getting the AC down to around 65-70vac from the wall. Of course each amp behaves a little differently, but when the vac is down that low, thats when things start happening. With the amp starved of AC you have to push the front end to get some wind back in the sails. If you have ever tried the mxd 6-band with that aggressive frown curve on an amp running at full vac, it's ruins the tone, but when the amp is running way down at 65 vac it is the magic ingredient. the variac between the cab colors the the tone somewhat but reduces the overall volume very little. An attenuator seems to color the tone in a bad way. You've just got to try it for yourself with all the classic ingredients that James has layer out, then tweak from there.

[jnew]

Very very well said. And VERY TRUE. I'm in the air a bit on the MXR 6. It most definitely can add the magic but I think with just the amp, a little tweaking of the bias can fill the sails too but I still need to try it and confirm that. The MXR 6 is very convenient, especially if you can loop it in and out.

I made a short video about connecting the 2nd variac and it is uploading to YouTube as we speak. If it's successful this time, I'll post the link of course.

[jnew]

Well what do you know? I was able to get it to upload to YouTube this time. I started another thread with a link.

http://forum.metroamp.com/viewtopic.php?f=16&t=45092

[Strat78]

James, the vid is private!

[jnew]

I think it should be good now.