TG1 - advice from any one who has built it...

[GREAT TIME]

+1 on Igor's build docs

 

[duantro]

+1 on Igor's build docs

Pm me your email, I should have them

 

[LNS]

I'm just getting all my components together to build a DR-Zen but have a question about the 1N751a's. I'm looking at getting 100 so I can sit and match 4 pairs. DR sent over a mouser cart with 1N751A's added to it but they are quite expensive at £151 for 100. I can get hold of 100 Motorola 1N751A'a for £40 at the moment (the ones in the metal cases).

Flicking through this thread I can see some 1N751a's have been the source of excessive noise, has anyone successfully used matched Motorola 1N751A's in their build?

 

[thelivingroom]

I'm just getting all my components together to build a DR-Zen but have a question about the 1N751a's. I'm looking at getting 100 so I can sit and match 4 pairs. DR sent over a mouser cart with 1N751A's added to it but they are quite expensive at £151 for 100. I can get hold of 100 Motorola 1N751A'a for £40 at the moment (the ones in the metal cases).

Flicking through this thread I can see some 1N751a's have been the source of excessive noise, has anyone successfully used matched Motorola 1N751A's in their build?

I used Motorola 1N751A’s that I bought a lot of on eBay in my build of @fripholm’s version of the TG-1, and had no issues. Because others had issues with other brands, I was a bit worried and spent hours matching not just the pairs, but all 8 I needed to be within .001v at both 1k and 10k. Not sure if that or the Motorolas is what made the difference, but it sounds fantastic!

Here’s the post of my build:
[BUILD] fripholm's TG1 Zener Limiter boards - support thread

 

[LNS]

I used Motorola 1N751A’s that I bought a lot of on eBay in my build of @fripholm’s version of the TG-1, and had no issues. Because others had issues with other brands, I was a bit worried and spent hours matching not just the pairs, but all 8 I needed to be within .001v at both 1k and 10k. Not sure if that or the Motorolas is what made the difference, but it sounds fantastic!

Here’s the post of my build:
[BUILD] fripholm's TG1 Zener Limiter boards - support thread

Do each of the pairs need to be within .005v of each other to meet the neve spec?

I’ve measured 150 1N5231B’s and have found 8 perfectly matched pairs but each pair aren't within .005v of each other. Is the only requirement that each pair are matched?

 

[thelivingroom]

Do each of the pairs need to be within .005v of each other to meet the neve spec?

I’ve measured 150 1N5231B’s and have found 8 perfectly matched pairs but each pair aren't within .005v of each other. Is the only requirement that each pair are matched?

I think the only requirement is that each pair match, but due to others having trouble with the 751’s and me having plenty of time waiting for some backordered parts to arrive I went overboard and matched all of them. The 5231’s seem to be less troublesome for those who switched to them, so you’ll probably be fine.

 

[Ilya]

Is the only requirement that each pair are matched?

Yes, you need to have a good match within pairs, not between two pairs. To be on the safe side, you can match all 4 zeners so they are within .005V with each other.
751s are notorious for low level and noisy output. This is much more critical than matching IMHO.