V1 in the MTS amps

[kojdogg]

Hey-- please forgive the ignorance here and if this has been asked and answered before.
Does changing V1 in the MTS amps yield the same kind of tonal benefits that it would in a non-modular amp?
I have this little collection of really nice tubes (60's long black plate Mullards, Raytheons, Fishers, and the like) that I assembled for some pricey tube mics and pres I have or had (many of those were sold once I switched from being a mic/preamp/compressor addict to a guitaraholic) and it'd be cool if I could improve the sound of my MTS amps and modules by popping one of the tubes in each of them.

 

[JKD]

Yes, v1 on the module has most effect..it's the one on the left looking at it from the control side/front.

 

[kojdogg]

Yes, v1 on the module has most effect..it's the one on the left looking at it from the control side/front.

Cool-- thanks a lot!

 

[nikki-k]

I thought V1 was actually installed in the amp or rack unit, and V2 of a typical circuit would be the left tube (from face of module), and V3 the right?

Effectively, V1 is therefore "shared" by each module, which provides the sculpting of the remainder of the preamp section... yes?

Still scouring and learning about the whole MTS thing... would love to see a schematic of the head/rack front end, then an example module, and out from there (differs by equipment post module, no?)

 

[jmgman70]

Yes, v1 on the module has most effect..it's the one on the left looking at it from the control side/front.

According to Egnater this is a correct statement 8)

 

[JKD]

I recall a post from Jeff or Bruce (Egnater) stating that the 'v1' in the heads is only used as a buffer/driver stage.....

I've changed v1 in the heads and it does make a difference, some are subtle changes..others less so.

 

[nikki-k]

See, this is why I love the old stuff. Look inside, easy to trace. Plus, most schematics (even Boogie) can be found these days. Waiting for UPS... maybe I will try Randall support... hehehe...

 

[okstrat]

FYI, most boogie schematics out there are wrong.

 

[nikki-k]

The studio one was accurate *enough*
IIC was decent, few IIC+ were off.

Anyway... turns out the only way to get answers, according to Randall, is to hope a tech will answer here, or become a service center and request docs.

I seriously need a Midol today... between USPS and that phone call.. well, glad I do not drive.... Attitudes all around today

I need to spend several hours digging thru here. Would rather not tear down my RM4 today to figure this one out.

 

[KillTone]

I have tried several NOS tubes (RCA, Raytheon, Amperex, Sylvania, etc.) in my RM100 and in some modules. I did not hear much of a difference when I used them in the head In the clean(er) modules they make a big difference in the warmth and complexity of the tone, but not much help in the higher gain modules. This is subjective of course, but that is the way I heard it.

They made a much bigger difference in my Boogie.

 

[nikki-k]

Collecting threads...

M4 tube info
Egnater MOD series info

From Jeff's reply, it would seem that if the RM series follows the Egnater stuff, the RM---'s V1 would be the same as V1 in a *typical* guitar amp head, but utilizing only one triode. It *should* follow that V1 and V2 of a module do the gain stage(s), and tonestack. Back out of module, off to (tube buffered?) fx loop(s), PI (in heads), etc.

Pete? Randall guys? Pretty please?

 

[Soulinsane]

V1 would be the same as V1 in a *typical* guitar amp head, but utilizing only one triode. It *should* follow that V1 and V2 of a module do the gain stage(s), and tonestack. Back out of module, off to (tube buffered?) fx loop(s), PI (in heads), etc.

Pete? Randall guys? Pretty please?

You are absolutely correct.

 

[nikki-k]

Thx!

I actually broke down and disassembled my SL+ and did a quickie trace... appears to follow that logic. Did not open the RM4 tho... figured if V1 in it (and the heads) is doing input gain, then it would be odd to repeat this in every module.

Love the simplicity of single channel PTP/*breadboard* amps... then again, get inside an AC15... lol...

 

[Soulinsane]

I have a mod I want to post that includes the other half of the V1 tube. It provides for an added gain control knob before the modules. It shouldn't be done by first time solder monkeys. Once I'm done testing with my RM100 I'll tell how it is done.