Klein and Hummel UE-100 EQ Matching

[rekkoned]

Hi there everyone,

so I've recently been lucky enough to get a pair of K&H UE-100s which have been sat in a studio unused for at least a decade.
I'd love to put them to work on some masters but it seems they're not matched, or have at least gone out of being matched while being dormant.
In practical terms, the audio put through them seems to be put out of phase (even when no eq bands are engaged). If I send just a kick drum through both of them, the return is a flammed version of the kick drum.
I was thinking this could also be because just a case of how my hardware sends are set up, but this isn't the case with other outboard gear I have so that's a little doubtful.
Would anyone have any pointers on matching these back together? Would this involve just re-tubing both of them?

Thanks in advance!
- Honza

 

[gyraf]

you need to figure out what exactly goes wrong in there, in what stage. the circuit itself is intrinsically precise

 

[rekkoned]

you need to figure out what exactly goes wrong in there, in what stage. the circuit itself is intrinsically precise

Yeah that's kind of what I thought. Unfortunately my skills in electrical engineering aren't at that level so will probably have to send them off to a tech. It seems that the output levels of the units are different aswell so might be a bigger issue than i initially hoped. Cheers for the insight!

 

[gyraf]

Perhaps try massaging the switches thoroughly - noting if anything changes along the way..

For long-unused ue100s, this is no.1 thing to try..

 

[rekkoned]

Perhaps try massaging the switches thoroughly - noting if anything changes along the way..

For long-unused ue100s, this is no.1 thing to try..

Yeah I did give them a good De-oxit bath haha! Maybe not enough though to be fair, I was airing on the side of caution to not cause any damage.

 

[pucho812]

Lucky indeed.
Perhaps capacitors need changing.
Perhaps you got bad tubes.

 

[Gold]

Congratulations on owning the best EQ ever made. The switches are touchy. Getting them to be reliable is tricky. There are precious few EL caps to change. Once it’s working don’t skimp on the tubes in the Input/Output section. Use something like Valvo. The tubes in each EQ section don’t matter as much.

 

[rekkoned]

Lucky indeed.
Perhaps capacitors need changing.
Perhaps you got bad tubes.

Yeah that's kind of the area I was thinking on focusing on aswell. The caps look like theyre in pretty good condition on visual inspection, but defo need to do some further testing!

 

[rekkoned]

Congratulations on owning the best EQ ever made. The switches are touchy. Getting them to be reliable is tricky. There are precious few EL caps to change. Once it’s working don’t skimp on the tubes in the Input/Output section. Use something like Valvo. The tubes in each EQ section don’t matter as much.

Haha thanks! I've been using them on mono sources and they've been an absolute dream so far! The switches look incredibly complex so that does make sense, do you think it would just be a case of cleaning them more or testing specific things on them to get them to a more reliable point?

 

[Gold]

Haha thanks! I've been using them on mono sources and they've been an absolute dream so far! The switches look incredibly complex so that does make sense, do you think it would just be a case of cleaning them more or testing specific things on them to get them to a more reliable point?

I think It’s cleaning them and physically inspecting them to make sure they are doing what they should be doing. Don’t overlook the molded RCA connectors. They get wonky too.

 

[rekkoned]

I think It’s cleaning them and physically inspecting them to make sure they are doing what they should be doing. Don’t overlook the molded RCA connectors. They get wonky too.

Some of the rotary switches have definitely been a little too stiff and stuff so I will defo get on cleaning and inspecting everything some more! Thank you so much for the tips. Also btw, I'm a huge fan of your master on Galatic Melt from Com Truise, amazing work!

 

[Gold]

Thanks!