GROUP BUY: Universal Audio 176 - a 100% faithful recreation of a legend! CLOSED!

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mohausler

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Feb 27, 2017
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Hello. Quick question. Does anybody know if a gz34 valve that has a smaller than normal footprint? I’ve used the bigger 372x power transformer for my unit. And it’s already touching the big can capacitor on one side. Can’t seem to fit the gz34 in. The black base rim is too wide. Has anybody else had that problem? The valve I have right now is a sovtek. Also tried a Mazda. Same issue. Anyone?
 

Phrazemaster

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Hey mohausler I wish I could help you, haven’t gotten to that stage yet.

I do have a question - are people using solid core or stranded wire for this project?

thx,
Mike
 

Potato Cakes

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Hello. Quick question. Does anybody know if a gz34 valve that has a smaller than normal footprint? I’ve used the bigger 372x power transformer for my unit. And it’s already touching the big can capacitor on one side. Can’t seem to fit the gz34 in. The black base rim is too wide. Has anybody else had that problem? The valve I have right now is a sovtek. Also tried a Mazda. Same issue. Anyone?
How much wider is the glass than the socket base of your GZ34 tubes? I'm using a larger power transformer and I don't have that issue.

Thanks!

Paul
 

eskimo

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Mar 30, 2006
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A couple of question for you 176 users:
  • How often do you find yourself having to balance the unit?
  • Do you find the verniers crucial when using 2 dB step Davens?
I'm building a non hinged unit and trying to figure out what I must have on the front, what I can put on the back, and what I can leave out entirely.
 
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Potato Cakes

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Hi Paul, thanks so much. Was it hard to keep the wires in place? Did you end up gluing them down, or how did you manage it? I like the idea of solid core but then again solid core breaks so easily...

Anyway thanks so much!

Mike
I didn't have much trouble managing it. In certain places I used small zip ties once I decided on cable routing.

Thanks!

Paul
 
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Phrazemaster

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I decided to add a "Bypass" switch. I am wondering if I need to actually setup a pair of relays or can I just use a bypass switch?

If I do a bypass switch I'm assuming I'll need shorting?

Thanks in advance,

Mike
 

Potato Cakes

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I decided to add a "Bypass" switch. I am wondering if I need to actually setup a pair of relays or can I just use a bypass switch?

If I do a bypass switch I'm assuming I'll need shorting?

Thanks in advance,

Mike
The attack knob has a switch built in that disengages the compressor function. Are you talking about a hardwire bypass?

Thanks!

Paul
 

Potato Cakes

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It just depends on your preference I suppose. As you know, if you just use a switch the balanced input has to travel to from the back panel to the front and then back again. Shorting is probably preferable but if not you could use a resistor or capacitor to mitigate any popping if there is any.

Thanks!

Paul
 
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Phrazemaster

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It just depends on your preference I suppose. As you know, if you just use a switch the balanced input has to travel to from the back panel to the front and then back again. Shorting is probably preferable but if not you could use a resistor or capacitor to mitigate any popping if there is any.

Thanks!

Paul
Thank you Paul.

Obviously a relay is more work, but would that be better somehow? I thought it was cleaner especially over time due to switch arcing and oxidation? Would it help with clicks and pops as well?

also the relay could be close to the source, so long runs not necessary.

thx

mike
 

eskimo

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  • How often do you find yourself having to balance the unit?
I'm building a non hinged unit and trying to figure out what I must have on the front, what I can put on the back.
Still intrigued about this ^ if anyone has experience.
 

beatnik

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Oct 18, 2009
Messages
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Dorset, UK
If you used 600 ohm t pad attenuators potentiometers you can avoid the stepped attenuator + vernier configuration of the original.

Blore-Edwards in the UK sells decent quality 600 ohm t pad pots


I think the balancing controls can be left internally or perhaps at the back, but if you want the vu meter to always be precise put the meter 0 trim on the front panel, this can drift sometimes.

This is a useful part for mounting this control on the front panel

 

j.colt

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Aug 6, 2020
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Washington DC
Hey guys, almost done sourcing parts! Looking to see if anyone on here has an API 361 VU Meter, UTC 0-17 Shield and A-33 Shield? Thanks!

Also for those looking for high quality vintage design, I found a 10HY choke made Classic Tones. It's Paper Layer wound like the vintage era ones using premium materials. Made in USA. Here's the link: Vox AC15 Vintage Choke, 10 Hy

Also found that Aerovox has a new name, its CD Aero. They still sell their capacitors, but still waiting on a reply to see how to purchase. Doesn't look like they have them at retail.

Hoping all the builds are great or are coming along great!
Good find about the choke! It looks like Classic Tones is no longer making them, so I hastily ordered a couple from a retailer... but these things are huge!! Were you able to fit them in the chassis? I am a bit worried about fit because I am planning on putting a big T-bridge attenuator on the output and it looks a bit tight.
 

j.colt

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Aug 6, 2020
Messages
17
Location
Washington DC
One question for those with original 175/176: Are the three rotary switches for GR, Meter and Test shorting or non-shorting? The BOM mentions shorting but the big collection of photos posted earlier in this thread shows that they are probably all non-shorting. Does anyone have some insight? Does it matter? Thank you!
 

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