Peavey Valvex 6x2 tube mixer - impedance matching...?

[tonedude]

I've bought this all tube mixer to use it as a summing mixer etc in my home studio.

There is very little info on the internet on this mixer but I found out that it initially was built to be used in guitar amp rigs and therefore have high output impedance, 47kOhm. As I intend mostly to use it hooked up to my audio interface (a Fireface 800 with line inputs with 10kOhms input impedance) I wonder how to match the Valvex output to the Fireface line ins?

Can I use transformers or is there another good DIY solution?

Should I care? Is this mismatch really a problem?


Thanks for helping!
/ Mattias

 

[pucho812]

is it unbalanced output? unbalanced input?

 

[tonedude]

is it unbalanced output? unbalanced input?

Unbalanced in and out!

 

[JohnRoberts]

I've bought this all tube mixer to use it as a summing mixer etc in my home studio.

There is very little info on the internet on this mixer but I found out that it initially was built to be used in guitar amp rigs and therefore have high output impedance, 47kOhm. As I intend mostly to use it hooked up to my audio interface (a Fireface 800 with line inputs with 10kOhms input impedance) I wonder how to match the Valvex output to the Fireface line ins?

Can I use transformers or is there another good DIY solution?

Should I care? Is this mismatch really a problem?


Thanks for helping!
/ Mattias

You can just use these as is. Yes it was designed for use with premium guitar paths. Not that Peavey sold many, but peavey made enough tube guitar amps that a few artists used these in their high end rigs.

I recall when this product was obsoleted, and one of my tasks was to figure out how to move them...  I even experimented with increasing the voltage gain so it was easier to overload and make rounder tube sounds...  No love.. I still couldn't give them away to studio types... Something about the Peavey brand turns off those studio guys.

Enjoy but it wasn't designed as a sound effect, it was a simple, clean mixer for a few high impedance sources.

JR

 

[okgb]

I always wanted one for the intended purpose , but only saw full ? retail prices
which seemed a bit high for me for mostly bar gigs
I still want one .................. never see them on fleebay

 

[tonedude]

I've bought this all tube mixer to use it as a summing mixer etc in my home studio.

There is very little info on the internet on this mixer but I found out that it initially was built to be used in guitar amp rigs and therefore have high output impedance, 47kOhm. As I intend mostly to use it hooked up to my audio interface (a Fireface 800 with line inputs with 10kOhms input impedance) I wonder how to match the Valvex output to the Fireface line ins?

Can I use transformers or is there another good DIY solution?

Should I care? Is this mismatch really a problem?


Thanks for helping!
/ Mattias

You can just use these as is. Yes it was designed for use with premium guitar paths. Not that Peavey sold many, but peavey made enough tube guitar amps that a few artists used these in their high end rigs.

I recall when this product was obsoleted, and one of my tasks was to figure out how to move them...  I even experimented with increasing the voltage gain so it was easier to overload and make rounder tube sounds...  No love.. I still couldn't give them away to studio types... Something about the Peavey brand turns off those studio guys.

Enjoy but it wasn't designed as a sound effect, it was a simple, clean mixer for a few high impedance sources.

JR

Ok, thanx for your info and answer!

There is really not much info to find about the Valvex on the web! Peavey has no manual on their site and "googling" for info is no big success ... I read at gerslutz that Jim Williams at audio upgrades rates it as great summing mixer, especially when the power supply and audio path is upgraded with better caps. I'm picking it up at the postoffice tomorrow... should be great fun!

/ Mattias

 

[pucho812]

I always wanted one for the intended purpose , but only saw full ? retail prices
which seemed a bit high for me for mostly bar gigs
I still want one .................. never see them on fleebay

here ya go. fleebay. I am not in anyway shape or form associated to the auction.

http://www.ebay.com/itm/Peavey-Valvex-Stereo-Tube-Mixer-/320956999659?pt=LH_DefaultDomain_0&hash=item4aba8727eb

 

[okgb]

Thanks for digging it up , at 400.00 I start to think I should just build one
then remember I'm backlogged , then get dizzy and hit my head and wake up
and start wanting things again  , sometimes I just practice instead

 

[JohnRoberts]

I could have made you a great deal on these when I was trying to blow them out...  15 years ago or more... 8)

JR

 

[okgb]

Yeah , too bad for me
Are they 1/2 12ax7  each channel for gain passively mixed into a cathode follower out
or is there more to it than that ? [ and returns are also passively mixed ? ] And what was the idea behind the color scheme ?

 

[ruffrecords]

Yeah , too bad for me
Are they 1/2 12ax7  each channel for gain passively mixed into a cathode follower out
or is there more to it than that ? [ and returns are also passively mixed ? ] And what was the idea behind the color scheme ?

I was wondering about that - it seems to have some sort of per channel  FX send as well as pan AND two FX returns. How on earth do you do that with just 6 triodes? Any pics of the rear connectors for clues?

Cheers

Ian

 

[JohnRoberts]

I know nothing about this other than it was a simple guitar mixer, so the effects were pedals..

It was probably designed by Jack Sondermeyer a good tube guy, but nothing fancy, just intended  for a good sounding guitar rig, so proper impedances and levels for that. Nothing special or fancy.

JR

 

[tonedude]

I'll put up pics of it when I have it at home!

I'f I would like to have balanced out on this thing, is it as simple as hooking up a transformer or do i need to ad some extra circuitry to adapt it to a good line out transformer?

 

[ruffrecords]

I'll put up pics of it when I have it at home!

I'f I would like to have balanced out on this thing, is it as simple as hooking up a transformer or do i need to ad some extra circuitry to adapt it to a good line out transformer?

Depends very much on the circuit used. Those pics might give use a clue. Did it come with a User Manual?

Cheers

Ian

 

[JohnRoberts]

Just guessing this was designed to plug into a guitar amp input so I wouldn't expect much output current drive capability.  I recall taking a gain modified unit to listen through on my home hifi and it had no problem driving a typical line level impedance, but i expect this was designed with the typical Peavey sharp pencil, for unbalanced interfaces.

PS: I didn't hear any tube magic on my home hifi, not that I really expected too, but i was hoping for some.

JR

 

[bockaudio]

I recall when this product was obsoleted, and one of my tasks was to figure out how to move them...  I even experimented with increasing the voltage gain so it was easier to overload and make rounder tube sounds...  No love.. I still couldn't give them away to studio types... Something about the Peavey brand turns off those studio guys.
JR

Interesting, it looks like a good idea. Usually you have to change model #s etc to get media & market attention back on a unit like that. I wonder if B*rringer could do it now for $20.
Not knocking the function, but it wasn't just the Peavey name that kept studio guys away, the graphics on that thing are awful!
BTW JR do you know anything about the "transtube"? Hartly's white paper on the subject is more sales than information....

 

[JohnRoberts]

I recall when this product was obsoleted, and one of my tasks was to figure out how to move them...  I even experimented with increasing the voltage gain so it was easier to overload and make rounder tube sounds...  No love.. I still couldn't give them away to studio types... Something about the Peavey brand turns off those studio guys.
JR

Interesting, it looks like a good idea. Usually you have to change model #s etc to get media & market attention back on a unit like that. I wonder if B*rringer could do it now for $20.
Not knocking the function, but it wasn't just the Peavey name that kept studio guys away, the graphics on that thing are awful!
BTW JR do you know anything about the "transtube"? Hartly's white paper on the subject is more sales than information....

For the record the tube mixer was never intended as a studio product... I was just looking to move it there due to the irrational attraction to tube paths. My judgement of customer opinion was formed during years as lead engineer for the recording products division (AMR).

I did not work on the transtube amps myself, but knew the engineers who worked on them. I even recall prototype amps showing at at jam sessions at my place during some of my house parties, and at occasional local bar band gigs, when the engineers were moonlighting in a band.

There are patents on that technology so you should be able to get real explanations for how it works there.

As i recall it used some dynamic circuit tricks to mimic the event driven short term bias shifts inside tubes as they respond to saturation overload. I am neither a tube guy or a guitar guy, but even I could hear the improvement over a cheap solid state amp realized from a few dollars of added solid state circuitry. Even cooler, the transtube technology could mimic the same effect as running a real tube amp down on a variac to get the saturation effect all the way down to very modest levels. Other clever circuits synthetically raised the output impedance of the solid state amps to be more like tubes amps, for driver cabinet interaction, but this too could be limited to HF or LF only for even more control of the effect..

Being able to control and vary these aspects of tube amp sound considered euphonic is pretty powerful. These were never exactly the same as real tube amps, but for live performance, especially on a budget, they did not suck. I recall when these were new, the majority of listeners in our NAMM show booth could not pick which was which between transtube and real tube amps in a live single blind test playing a guitar through them.

JR 

 

[bockaudio]

Thanks, John.

 

[tonedude]

Adding some pictures...

Minimalistic circuit design... 

Added larger/more caps in PSU which made it less prone to distort bass frequencies. If I hit it really hard I can make it distort, a little, not much really... Sounds good though!

I plan to upgrade caps in the audiopath, any suggestions? Wima MPK?


Thanks for helping me out!
/ Mattias

 

[okgb]

Nice pic , thanks
I have to agree though , some of the peavey color / art schemes
remind me of fast food places here they decorate it  to NOT be comfortable
or make it look cheap so you get swayed thinking it is costwise
bad taste or poor judgement ?