Diezel VH4 DeKompression mods?

[VC4Ever]

I have a VH4 with the mod. It is awesome. If you want to open up the amp from its compressed nature then this will do it. Plus the mod is a pot in the back of the amp and can be completely bypassed with it all the way down. I was lucky enough to buy a used VH4 with the mod already done so I have no experience actually sending the amp in to get it done.

Plenty of expensive amps get modded.

 

[Tone Monster]

I have a VH4 with the mod. It is awesome. If you want to open up the amp from its compressed nature then this will do it. Plus the mod is a pot in the back of the amp and can be completely bypassed with it all the way down. I was lucky enough to buy a used VH4 with the mod already done so I have no experience actually sending the amp in to get it done.

Plenty of expensive amps get modded.

Thanks!

 

[MississippiMetal]

It's probably nothing more than a pot that regulates the negative feedback.

 

[VC4Ever]

I have a VH4 with the mod. It is awesome. If you want to open up the amp from its compressed nature then this will do it. Plus the mod is a pot in the back of the amp and can be completely bypassed with it all the way down. I was lucky enough to buy a used VH4 with the mod already done so I have no experience actually sending the amp in to get it done.

Plenty of expensive amps get modded.

I like my warranty. Cant risk it.

I completely understand. If I were to buy new I would be worried about warranty too especially spending that much full price.

 

[rwarner]

I don´t call myself a super tech because I can
switch on a solder pen. Why don´t send an email
to peterdiezel (at) diezelamplification (dot) com
and I will support you. And I don´t have to be sad
about any destroyed Diezel amps. There is also a
big service manual for skilled techs.

With all due respect Mr. Diezel your comment is very disrespectful.
When you used to mod Marshalls back in the days I'm sure Jim Marshall did not look down on you just because you expanded your own ideas onto an already great sounding Marshall amp.
I met Jim Marshall once and he was a true gentleman !

 

[rwarner]

It's probably nothing more than a pot that regulates the negative feedback.

I'm an engineer by day and know that actually the mod has something to do with re-routing the entire tone stack which is cathode follower driven.

 

[Shark Diver]

If absolutely nothing else except the mod was engaged in those clips - then it mostly sounded pretty good. I'd probably need to be in the room to believe some of those don't have other tweaking going on. And it's ok to mod anything - it's yours.

 

[Giga]

It's probably nothing more than a pot that regulates the negative feedback.

I'm an engineer by day and know that actually the mod has something to do with re-routing the entire tone stack which is cathode follower driven.

Really ? With a pot ?

Care to share some more on the subject ? You got me interested here

Giga

 

[FIREBALL]

ANYONE HAVE CLIPS OF THIS ON A HERBERT

 

[Rødskjegg]

ANYONE HAVE CLIPS OF THIS ON A HERBERT

There are some clips on the site.

 

[Peter Diezel]

I don´t call myself a super tech because I can
switch on a solder pen. Why don´t send an email
to peterdiezel (at) diezelamplification (dot) com
and I will support you. And I don´t have to be sad
about any destroyed Diezel amps. There is also a
big service manual for skilled techs.

With all due respect Mr. Diezel your comment is very disrespectful.
When you used to mod Marshalls back in the days I'm sure Jim Marshall did not look down on you just because you expanded your own ideas onto an already great sounding Marshall amp.
I met Jim Marshall once and he was a true gentleman !

Sir,
I´m not disrespectful but I have to live with this issues
every day. At the end the work is on me. I met Mr. Marshall
many times and he told me about good and bad "modifications".
I was one of the bad guys

 

[Heritage Softail]

If the mod is that great, I would think the very friendly folks at Diezel could help you out if you asked.

An unauthorized mod on a $$$ amp does not sound like a good idea to me.

If you can indeed decompress the amp as claimed and still have the stock tones available, sounds interesting. If Peter can create all those amps, I don't think one mod will baffle him. Just saying.

 

[Peter Diezel]

The "decompression mod" or whatever it is called
makes only sense for amps made before 2005.
It´s a simple resistor replacement which gives
the circuit more presence when you get into
distortion. The mod is described in our service
manual since a long time. I don´t would recommend
to replace the resistor by a pot. If the pot and the
wiring is not on the right position it can cause
some oscillation issues. If you are sure you REALLY
need this send an email to:
peterdiezel (at) diezelamplification (dot) com

I need the version number of your PCB, your phone number
and address.

Cheers,
Peter

 

[rwarner]

Jens' mod has nothing to do with that presence resistor.

 

[Tone Monster]

Jens' mod has nothing to do with that presence resistor.

Enlighten us. What is involved with the mod, generally speaking.

 

[MississippiMetal]

Oh Jesus, here we go. An engineer to the rescue!!

I call bullshit on that. Diezel amplifiers are well known to utilize a tremendous amount of global feedback that results in the compression and damping quality. Even the description on Jens' site of the mod strongly suggests that it's a mod that tinkers with the -FB.

Our newly developed DeKompression Mod opens up your amp and dramatically increases:

Low + high frequency response
Clarity
Sonic pressure
Pick attack
Dynamic range
Low volume playability

Especially modern amps suffer from an overly compressed design which chokes it's true abilities. This mod will unleash the amp's hidden strengths.

The original factory built in compression can be turned back on using a switch we install, so you can always go back to the original factory setting, original factory tone.

 

[steve_k]

 

[MississippiMetal]

 

[1meanplexi]

I really think to each his/her own! If ya wanna paint it pink, well that is what you do. The reason I bought the VH4 to my ears, it is perfect. Not to mention, I got sick of spending hundreds of fucking dollars and waiting for months at a time having existing amps modded to get them where they should have been coming out of the factory in the 1st place!!!!! Just my .02!

 

[maynardo]

this

Oh Jesus, here we go. An engineer to the rescue!!

I call bullshit on that. Diezel amplifiers are well known to utilize a tremendous amount of global feedback that results in the compression and damping quality. Even the description on Jens' site of the mod strongly suggests that it's a mod that tinkers with the -FB.

Our newly developed DeKompression Mod opens up your amp and dramatically increases:

Low + high frequency response
Clarity
Sonic pressure
Pick attack
Dynamic range
Low volume playability

Especially modern amps suffer from an overly compressed design which chokes it's true abilities. This mod will unleash the amp's hidden strengths.

The original factory built in compression can be turned back on using a switch we install, so you can always go back to the original factory setting, original factory tone.

it's probably just a pot in series with the NFB resistor, I think Rivera amps call this pot 'focus' and the CAA pt100 just calls it NFB