[BUILD] fripholm's TG1 Zener Limiter boards - support thread

[Mike Havok]

Quick question:

SC and Mode switches, MBB or BBM?

Thanks

 

[fripholm]

If you have access to MBB, use these but you shouldn't have a problem with BBM either. I only had the latter kind for my builds and there are no negative side effects.

Some have reported loud popping noises when BYPASS switching the compressor and my mono unit sometimes does that, too. So it might be a good idea to use make-before-break in this position. However, my stereo unit, which uses relays switched by those rectangular console style switches, does not pop.

 

[Mike Havok]

Thanks!

 

[zerodb]

Stupid question time:

If I'm reading it right, then comparing the schematics for this with the old Fester schematics, D13 has been added.
Is there any rationale for this?
Also, R41 appears to have been changed to 62k from 27k, if I'm reading it right...? Is this change to compensate for adding D13?

I see a few other resistor and capacitor value changes, but nothing particularly significant.

Are there other changes to be aware of? Which is closer to the EMI/Chandler design?

Cheers!

 

[fripholm]

It's been a while but if I remember correctly, I was trying to lower the distortion and/or noise a bit by lowering the threshold so the compression kicks in a little earlier. This increased the gain in the sidechain and with it the compression ratio. In this design a higher ratio also comes with a much harder compression knee hence D13 was added and the following resistor had to be changed to compensate for the higher gain. Despite those changes, I wanted the comp/lim knee to be like the original.

In the end, the threshold is only slightly lower than the original but the overall character should be the same.  One could argue that it wasn't even worth it  :

For other changes see the build guide and this thread. It's all been discussed before. AFAIK Fester's version is true to the original EMI schematic - I don't know anything about Chandler's version...

 

[Chad]

Just thought I'd show my finished build
Thanks fripholm for the project, the guide was very comprehensive.
I ended up making my own knobs and silkscreening a frontpanel, 3D printed Sifam style coverings for the cheap eBay VU meters.
Putting the power supply in a remote box cured my hum woes, as well as keeping the audio transformers away from each other.

Hit me up if you're interested in knobs for this project

 

[fripholm]

What a beautiful unit - congratulations! Thanks for sharing.
___________________

A few days ago I was made aware that my description in the guide to adding the HOLD mod was wrong. In the meantime I have revisited the respective page in the guide and re-uploaded the file.  Just download again from the link in the first post.

It's a very simple mod but the way it's implemented you will loose Auto Release that the original didn't have anyway. I have (temporarily) performed the modification myself and - as it is now - can confirm that it's working.

My apologies to anyone who has tried it  :-[

 

[core13]

It's been a while but if I remember correctly, I was trying to lower the distortion and/or noise a bit by lowering the threshold so the compression kicks in a little earlier. This increased the gain in the sidechain and with it the compression ratio. In this design a higher ratio also comes with a much harder compression knee hence D13 was added and the following resistor had to be changed to compensate for the higher gain. Despite those changes, I wanted the comp/lim knee to be like the original.

In the end, the threshold is only slightly lower than the original but the overall character should be the same.  One could argue that it wasn't even worth it  :

For other changes see the build guide and this thread. It's all been discussed before. AFAIK Fester's version is true to the original EMI schematic - I don't know anything about Chandler's version...

is it possible to emulate the comp 2 with this mode?

thank you

 

[fripholm]

As the last batch sold out recently I've decided to do another one. AVAILABLE NOW!

Board revision v2.5 adds some small improvements that involve a few trimmers to help the fine tune process. All of those changes are optional and do not change the circuit or sound in any way.

The guide has been updated as well to reflect the changes. Just re-download the file linked in the first post of this thread.

Thanks!

 

[weiss]

Just thought I'd show my finished build
Thanks fripholm for the project, the guide was very comprehensive.
I ended up making my own knobs and silkscreening a frontpanel, 3D printed Sifam style coverings for the cheap eBay VU meters.
Putting the power supply in a remote box cured my hum woes, as well as keeping the audio transformers away from each other.

Hit me up if you're interested in knobs for this project

Awesome, love it!

 

[andow]

Has anybody built the TG1 with VTB9046 on input and VTB2281 on output and can comment on the sound?

 

[andow]

Does anybody have two of these sidechain filter boards left?

 

[fripholm]

Does anybody have two of these sidechain filter boards left?

Write a PM to member ToBSn. Last time I heard he still had these left.

 

[andow]

Write a PM to member ToBSn. Last time I heard he still had these left.

I did, but never got a reply...  :-\

 

[ToBSn]

I did, but never got a reply...  :-\

Hi andow,

no pm received here. I have to check if there are some left.

 

[andow]

Hi andow,

no pm received here. I have to check if there are some left.

That's strange...  :-\

That would be great, thanks!

 

[electrisizer]

hey, ive finished the beast and to my ears it sounds great 

some notes:
lundahls in/out -  imho recommandable
putting the PSU external eliminated all PSU related noise (eg 60hz hum)
zener diodes from RND components are really low tolerance zeners (ive got matched ones pretty fast)
soundwise its an agressive compressor with alot of color/thd, similar to rev A 1176 but more classy sounding

thx fripholm!!!

here's some audio:
https://www.dropbox.com/s/lom2ky1wh3imow2/zener%20drums.mp3?dl=0

perhaps ill order a cnc engraved panel, mine looks very DIY

 

[iampoor1]

Does anyone have the build document foe the v2 version?

 

[fripholm]

Does anyone have the build document foe the v2 version?

PM'd you. 

 

[craig]

Hi
Which particular Lundahl models did you choose for your build

some notes:
lundahls in/out -  imho recommandable