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**Enzo** · 09-12-2021, 09:25 PM

I haven't studied the circuits, but my very first thing would be to try different speakers. More than any other thing, speakers affect your tone.

**modelmonster** · 09-13-2021, 03:13 AM

Yes i have tried different speaker combinations. still would like more bass .

**J M Fahey** · 09-14-2021, 06:28 AM

1) WELCOME to the Forum.

2) you throw SO MUCH DATA on the table, to boot some of it contradicting itself, that it�s impossible to answer in a coherent way.

Or answering would take 14 pages he he.

Originally posted by modelmonster View Post

Hello!
this is my first time posting.

I am a beginner when it comes to amps and only done a few minor jobs

(added a bias control to a carvin x 100b, replaced screen grid resistors, and biased tubes)
but i can solder well

I just acquired a sovtek mig 100. not the 100h but the 100.

.
I really like the amp , i think it is going to work great for me

I use the low input and get a good clean tone and use an opamp big muff for my dirty tone and it sounds great,

HOWEVER...

I would like to coax some more bass out of it .
I have the bass on 10 and have the treble on maybe 4
It seems very bright.

after some searching i have found some talk of the differences of the 100 vs 100h
the 100 h sounds like it has more bass and more gain.
i dont need more gain but i would like more bass.

a member here vintagekiki posted some info on the differences..( thank you vintagekiki)
here is a link to the discussion i found this info and also schematic links

https://music-electronics-forum.com/...equest?t=44493

http://music-electronics-forum.com/t40194/#post394505

here is what he posted as differences

Sovtek Mig 100(H) vs Sovtek Mig 100U
(The "u" he is referencing has the same values as my "100" in regard to these differences)

Basically amps Sovtek Mig 100(H) and Sovtek Mig 100U by schematics are relatively similar.
The differences are as follows.

Tube V1.2 (Pre amp)
Mig 100 (H) Rk = 4.7k (more drive)
Mig 100U Rk = 1k (more clean)

Tube V2.2 (Tone control)
Mig 100(H) tone control from anode (more drive)
Mig 100U tone control from cathode follower (less drive)

Schematic tone control equalization
Mig 100(H) associates to Fender amp.
Mig 100(H) middle control 10k (less middle regulation)

Mig 100U associates to Marshall amp.
Mig 100U middle control 25k
Mig 100U between treble and bass controls resistor 82k (when all pots at minimum bass is noticeable)

Tube V3 (Phase splitter)
Mig 100(H) Ca V3.1/ V3.2 = .1uF (more bass)
Mig 100(H) Cg1 V3.1 = .01uF

Mig 100U Ca V3.1/ V3.2 = .022uF (less bass)
Mig 100U Cg1 V3.1 = .022uF

Power supply
Mig 100(H) all elco = 220uF (hard)
Mig 100U all elco = 100uF (soft)

Ok, you show a long list of differences, what is the specific question here?

It looks like the "bass control"
and the" phase splitter" is where i can do a couple changes to get more bass

however i have a couple questions.

"Mig 100U between treble and bass controls resistor 82k (when all pots at minimum bass is noticeable"

Can i just lift one leg of this resistor to see if i like the change?

Why don�t you just try it, instead of asking us, and see whether you like it or not?
You are asking about taste, everybody has his own.

and also..

"Tube V3 (Phase splitter)
Mig 100(H) Ca V3.1/ V3.2 = .1uF (more bass)
Mig 100(H) Cg1 V3.1 = .01uF

Mig 100U Ca V3.1/ V3.2 = .022uF (less bass)
Mig 100U Cg1 V3.1 = .022uF"

should i change all 3 of the .022 caps?

Try it and decide yourself.

or just the 2 "Ca V3.1/ V3.2 = .1uF (more bass)"

and leave the ( Cg1 V3.1 = .022uF) alone rather than changing to it .01 uf.

Try it and decide yourself.

I hope this all makes sense as far as what i am trying to accomplish.

All we know is "you want more Bass".

Some of those Mods might give you more, some might not, just TRY them and decide.

In any case:

1) amps designed to be played LIVE (hint: besides that Noise Machine usually known as a Drummer) so LOUD usually:

* are BRIGHT to cut through, on stage.

* are BRIGHT to reach back seats at Club/Theater/Dance Hall, etc.

* are BRIGHT to keep some definition even when heavily overdriven.

* CUT BASS to keep distortion articulate and avoid farting.

Now you know why it sounds the way it does, it�s not by chance or a poor choice by designer, quite the contrary.

All those good choices backfire when Live Stage amps are played in a bedroom.

In a nutshell, that is a good amp, I would leave as is and pray for Covid�s end when we can all go back to normal (Live playing) .

IF you want the other model sound, rip its current guts and build a FULL copy of the other or sell it and buy the one you like.

Given the huge amount of Mods you want, those look like sensible options.

**modelmonster** · 09-14-2021, 04:07 PM

Thanks for the reply.
After reading my long post again ,, i totally understand it is long and confusing.
I believe i will edit the post .
but in the meantime the only mods i am considering are

there is a 82 k resistor between the treble and bass controls.

"Can i just lift one leg of this resistor to see if i like the change?"

I am a beginner so i wasn't sure if i could remove it completeley or if there was a reason it HAD to be there..

"Tube V3 (Phase splitter)
Mig 100(H) Ca V3.1/ V3.2 = .1uF (more bass)
Mig 100(H) Cg1 V3.1 = .01uF

Mig 100U Ca V3.1/ V3.2 = .022uF (less bass)
Mig 100U Cg1 V3.1 = .022uF"

and this again really a question of is there any reason if i change the value at Ca V3.1/ V3.2 to.1uf do i have to (or should i) change the value Cg1 V3.1 = .01uF. ?

I hope that makes more sense.
again i am still learning and maybe being more cautious when it come to experimenting than i need to be.

thanks for the replies

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Sovtek mig 100 more bass simple mod ideas

Sovtek mig 100 more bass simple mod ideas

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