UTC HA-100X

[bockaudio]

the new school version is not the same
CJ, what the physical dims of the bobbins & lams?

According to this picture:

in relation to the finger (more or less known size  8)) it looks like 375UI lams. I think that's the size you used in U195, correct?

Best, M

Yes! same size lams

 

[CJ]

31 UI  mag metals  80 supermalloy

same lam as the utc A-10 input and a bunch of other stuff

i think the utc ls-140 is mu metal lams,  higher inductance

if you see one for cheap on evilbay, try it out and let me know how it sounds

 

[thesystem]

CJ (or someone who knows), can you tell me how the sandcolored HA100X compares to the grey/black one? Are these the ones from the 70s and do they sound less like someone mentioned here? The info on the iron in red has the UTC logo, not TRW
Thanks

 

[khstudio]

CJ (or someone who knows), can you tell me how the sandcolored HA100X compares to the grey/black one? Are these the ones from the 70s and do they sound less like someone mentioned here? The info on the iron in red has the UTC logo, not TRW
Thanks

I've heard mixed reviews concerning the Black against the Gray versions & would also like to know more about what the differences are... sound wise or construction.

I currently have an older Black UTC HA-100X but haven't tried it yet.

 

[Phrazemaster]

I know this is a super old thread. But I'm just curious - what was the purpose of dissecting all those UTC HA-100x's? Is it to create a clone, or to be able to repair old UTC HA-100x's?

Really curious. Thanks.

Mike

 

[emrr]

Reverse engineering

 

[Phrazemaster]

Reverse engineering

Cool. For the purpose of...? Creating clones? Repair? Improving them?

Thx

 

[emrr]

knowledge

 

[shabtek]

Word

 

[CJ]

just curious.

found out they would be impossible to clone. too may turns, layered paper, foldback winding, special machinery,

 

[Phrazemaster]

just curious.

found out they would be impossible to clone. too may turns, layered paper, foldback winding, special machinery,

Gotcha! I had read some of your threads CJ with great interest, and I saw how meticulously you documented every stage of the tear-downs, and how many you tore down! So I just figured you must have been jonesing to create a clone, or to be able to repair them. Thanks for the update.

Were you able to put the tear-downs back together? Seemed like a destructive process!

Best,

Mike

 

[Phrazemaster]

By the way I wonder how good these are? I'm not even sure they still can get them, since they are out of stock...

https://www.studioelectronics.biz/sunshop/index.php?l=product_detail&p=1210

 

[CJ]

supposedly Magnetica has a lot of  UTC stuff and still makes them like the originals, never tried one,

David Jahnsen likes a 10K;10k  for an LA2a input as the original compressor has a lot of gain that sometimes can lead to overdrive situations when injecting a hot line level signal,

the Peerless K-241-D is a real nice input if you can find one,

 

[Phrazemaster]

Thanks for the info CJ!

 

[Phrazemaster]

Hi all,

I found a source for a pair of these, and the seller is sharing the following resistances on the tabs at the bottom:

Tabs.        Unit 1          Unit 2
1 & 2 =    11.1                11.1ohms
1 & 3 =    30.7                30.6 ohms
1 & 5 =    50.8                50.0 ohms
1 & 6 =    61.9              60.4 ohms
GR & 7= 3.05              3.06 Kohms
GR & 8= 1.55              1.49 Kohms

I tried searching this forum but these numbers didn't seem to be checked the same way as other resistances I've found here. Can anyone tell if these look to be right, or can point me to a listing? I would be buying through PayPal but I'd still like to have an idea if these might possibly be OK as seller claims.

Also I was reading that emrr you prefer the LS10's - would you use them in place of the HA-100x in an LA2A build?

Thanks kindly for any thoughts,

Mike

 

[CJ]

those numbers are good, snag em.

an LS-10 is just a A-10 in a big can that sells for way more than it is worth,

the HA-100 X is almost identical to the A-10 except it has a few more lams,

the HA 100 X has better shielding but the penalty for this is increased hi freq leakage to the 3 nested cans

 

[Conviction]

FWIW my pair of grey HA-100X's measures

1 & 2: 8,9Ω and 9Ω
1 & 4: 24,8Ω and 24,7Ω
3 & 5: 19,6Ω and 19,6Ω
3 & 6: 30,2Ω and 30,3Ω
7 & 9: 1,58kΩ and 1,59k
8 & 10: 1,61kΩ and 1,60kΩ

This is, of course, without the bonds between pins 3 & 4 respectively 8 & 9.

 

[emrr]

LS series equivalents always give different DC reading ranges, indicating different core and wire size. 

What I prefer may not be what you prefer. 

 

[Phrazemaster]

Thanks CJ, Conviction, and emrr. That gives me a little confidence and I'll go ahead.

It's fabulous to have folks like you guys sharing your wisdom - what an incredible board this is!

I'll post back when I get them and try to post a couple pix.

Thanks again!

Mike

 

[gridcurrent]

I don't want to rain on the HA-100x parade,
but for once will have to agree with the folks on this forum that refer to 600 ohm input devices as "archaic".
A suitable 1:2 step-up transformer works well on a LA-2a and it can be  bridging.
Unless one is doing what passes for "mastering", some gain is needed at the input of a LA-2a. 
There are a few rooms that employ transformer-less T4b based units.
They seem happy with small amounts of available compression, typically on a +4 dBu bus.


certain LS transformers were available in the HA package,



UTC transformers
resistance measurements in ohms

LS-10 dark grey, riveted badge, 3 strapped to 4
1 to 2 13.04
1 to 3 34.11
1 to 5 55.29
1 to 6 68.14

7 to 9 2289
8 to 10   2357



LS-10 black  HA case, 3 strapped to 4
1 to 2 12.9
1 to 3 33.77
1 to 5 54.11
1 to 6 67.18

7 to 9 2028
8 to 10   2110



HA-100x dark grey, riveted badge, 3 strapped to 4
1 to 2 11.25
1 to 3 31.47
1 to 5 52.89
1 to 6 64.67

7 to 9 1485
8 to 10   1551



HA-100x  type, light grey, from LA-2a re-issue,  3 strapped to 4
code 1766-01
1 to 2 11.61
1 to 3 32.42
1 to 5 52.99
1 to 6 64.45

7 to 9 1625
8 to 10   1638