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  •  » Midrange toroid and gain questions. Guidance required please...

#1 2013-03-15 07:11:08

Ultralinear
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Registered: 2013-03-13
Posts: 5

Midrange toroid and gain questions. Guidance required please...

Sorry in advance for the huge post!

A brief introduction: My name is Robin. I have a self-built bass guitar, an early 80s Gordon Smith GS-1 and I own a Simms Watts AP-100, Kelly 50W and a mid/late 70s V4B (to clarify... w/no distortion or MV). I also have a collection of late 70s/early 80s vintage synthesisers, amongst other assorted old equipment.

I tune to C and am after a thick powerful, yet organic distortion. I will be recording synths through my Ampeg, as well as bass and guitar. A huge guitar tone is my focus though.

My gain pedals include: ZVex SuperHardOn, TS-808, Catalinbread SFT, HiFi-mod Boss SD-1, Boss DS-1 (early), Boss HM-2 (MIJ), ProCo Turbo RAT (LM308), DOD Thrash Master, DOD American Metal, Big Muff (byoc), Boss Hyper Fuzz, Effector 13 TBD.

My questions... How marked of a difference does the toroidal inductor make to the midrange circuit tone? Is this something subtle you would only pick out through hearing your own guitar through a V4/V4B, adjusting the settings... or could you 'easily' pick it out from a recording? Can you articulate the difference in sound quality for me? Be as specific as you can please!

As I live in the UK, old Ampegs are unfortunately very rare. I haven't the chance to hear any others. Let alone compare them in person. YouTube videos appear almost invariably flawed for my questions (clipping of course!! or simply playing unsuitable music).

Please bear in mind, I'd like to use as much of whatever gain character I can squeeze out of the V4B itself, rather than the character of my pedals (which may not be the best idea!). I have searched the forum enough to know that the toroid isn't cheap but I'm willing to buy it (or have it wound) if the tone is lacking without.

What might you suggest to increase the gain of the V4B please? I have found the threads with the sensitivity mods (to match the V4); would you suggest modding one channel for maximum gain (I'll want less gain in the remaining channel for synth and bass recordings)?

Finally, which gain pedals (combination, order etc) from my list would YOU personally use to achieve as powerful a gain as possible from the V4B, whilst remaining true to its genuine character. i.e. I'm aware of bands (Converge, Black Breath) who have used the Boss HM-2 pedal through the V4 and it sounds huge but I'd like to sound a bit less aggressive.

I am fond of little highs, a very low midrange focused sound yet with tight bass.

I have/use a Fender (JBL) D-130, Altec 417, EV-12S. I record with a Reslo PRH and will be buying a trusty SM57 to compliment.

Thanks

Robin

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#2 2013-03-15 07:14:43

Ultralinear
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Registered: 2013-03-13
Posts: 5

Re: Midrange toroid and gain questions. Guidance required please...

I suppose I should have asked also whether replacing the discrete inductors with the toroid is an easy/possible task... on top of whether it is truly worthwhile!

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#3 2013-03-15 07:48:08

hangman
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From: Seattle Washington
Registered: 2006-09-04
Posts: 1848

Re: Midrange toroid and gain questions. Guidance required please...

The inductor certainly makes a huge difference in the functionality of the ampeg mid circuit. I can't think of any vintage guitar amps that had that kind of functionality.   Mesa-boogie and a number of other companies put graphic eqs in their guitar amps,  but while they were inductor based,  they were also transistor based... So not really the same thing.

I think the mid circuit is one of many things that makes the v4 and svt stand out.

As for increasing the gain of your v4b...  You could add a cathode bypass capacitor in the first gain stage of channel one or two.. But that is about it.  And it won't really boost the gain that much.   These preamps were not built to distort,  they were meant to drive the sh*t out of the power section.   
Again,  that is part of the ampeg sound,   It's why they take pedals so well.
Also,  I feel that adding the cathode bypass cap in the first stage changes the feel of the amp,  it makes it sound a bit more aggressive,  but at the cost of some of the bigger round feel that it has.   I sat with people and switched the cap in and out and (adjusting the volume for consistency) and everyone always leaves it the way it originally was.
Can I ask why you want more gain if you are using pedals anyway?

The torroidal inductor has a different sound to it for sure.   But I don't think that one is better than the other.   I prefer the softer/ rounder sound of the torroidal inductor,  but appreciate the more gritty and aggressive sound that the discrete inductors provide.

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#4 2013-03-15 15:15:25

Ultralinear
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Registered: 2013-03-13
Posts: 5

Re: Midrange toroid and gain questions. Guidance required please...

Thank you for such a concise answer!

Would it be possible to leave the original inductors in place... and mount a switch (at the back preferably) that engaged the toroid circuit instead? If possible/relatively easy: is there a reason I shouldn't? Other than the undesirable butchering aspect? (I may get a tech to undertake the mod) i.e. would it have to differ from the genuine early and late signal paths in some way? Or would the tone degrade somehow?

Regards your gain question. As you can probably tell by the number of completely different gain pedals I have: I've been keen to try many different setups...

I used to play metal and bought a dual rectifier (I have mellowed to a detuned prog style!). I switched the pre amp tubes to Mullard yellow label NOS. I changed the power section to EL34s too. I really liked the changes... but my tastes changed and I realised I preferred the sound of my Turbo RAT. I'm almost embarrassed by that fact! So I bought the Simms Watts (as a relatively clean platform, able to compete in volume with the Mesa) and sold the Mesa. I bought the Kelly head on a whim.

Since then, I've fallen for the Ampeg sound, initially through Queens of the Stone Age, then I discovered other bands who use the amp in different ways, with different pedals.

I'm aware that the QOTSA sound can be supposedly attained through using a ZVex SuperHardOn through the Ampeg V series. I'm keen to know whether any other options are advisable in order to coax gain from the pre or power section (now bearing in mind your comments about pre amp gain).

Is there a sensible way of pushing the power section more; without ruining the tone? (I'm not exactly keen to 'dime' all controls!).

I will be using a Sequis Motherload Elemental or a Richter attenuator in order to preserve the wildlife around my house. However, recordings will done in a more authoritative fashion! :-)

Is my choice of attenuator suitable? I haven't bought it yet...

Also, quite importantly: I've never heard my amp! I am yet to buy the UK-US voltage transformer for her.

Would you advise instead for me to modify the amp itself? Is there a reason to not use an external voltage converter?

Many thanks again.

Robin

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#5 2013-03-15 16:15:23

Ultralinear
New member
Registered: 2013-03-13
Posts: 5

Re: Midrange toroid and gain questions. Guidance required please...

I haven't checked yet whether mine is capable of the 230v mod... Is that in some way preferable over using a suitable external transformer?

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#6 2013-03-15 21:46:55

hangman
Banned
From: Seattle Washington
Registered: 2006-09-04
Posts: 1848

Re: Midrange toroid and gain questions. Guidance required please...

Many of the v4s had dual primaries.   So you might not need to change the transformer at all... May just require a minor rewire.

You could tell simply by counting the number of wires coming from your power transformer.   

I would say play the amp before you start wanting to mod it.   Don't try to make your amp into something it's not.  Try to find the right amp for you.   Trust me,  it makes a difference.

I honestly see no sense in having the toroidal inductor switchable with the discrete inductors.  It's really like having somebody mod your amp to have another exact same preamp with different brand of 12ax7s switchable with the original preamp. 
The discrete inductors are great.  Don't worry about it.  Your v4 is awesome as is,  don't try to make it something it's not.
That's what you learned with the Mesa boogie,  they give you all these switches and buttons, and lights and ultimately they only do one thing well. 
And even then,  the ampeg with a SuperHardOn kicks a rectifier to the curb..

I have no opinion on the attenuator,  I don't ever use them, so I can't really comment.

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#7 2013-03-16 10:05:06

Ultralinear
New member
Registered: 2013-03-13
Posts: 5

Re: Midrange toroid and gain questions. Guidance required please...

Thanks again!

I know how it may come across. I have friends who want to highly modify their cars when purchasing a slightly different model makes far better sense. I assure you it isn't quite that simple in this case!

I would have bought an early 70s V4B but I think you can imagine how rare they are over here. I waited for months for one to appear and drove for over 4hrs each way to pick it up!

Some of those bands that I like the tones of use the late 70s version by the looks of it anyway. I won't lose sleep about it! There's a high probability I may prefer it!

I'll take a look at my transformer when I get home.

If I could buy you a beer, I would.

I'm going to make a donation later.

Cheers

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#8 2013-03-16 16:29:58

hangman
Banned
From: Seattle Washington
Registered: 2006-09-04
Posts: 1848

Re: Midrange toroid and gain questions. Guidance required please...

I think my main point is that the two versions are so similar that it isn't worth bothering.  It isn't as though ampeg changed the inductor values,  they just used a different inductor format. 
They do have different characteristics to the sound of the mids,  but this is only really obvious when the mids are really boosted.  Between 10 and 2 O'clock you'd be hard pressed to notice much of a difference.

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