Sonomatic delay: OPA2134 or not?

[giovanni]

I am in the process of building the Sonomatic and I don't have OPA2134s. I know I may be able to use TL072s, but I was wondering if it will make an audible difference? Has anybody tried it? Should I just YOLO it?

 

[Cybercow]

Go YOLO. It won't break anything if you use TL072s. You can always use sockets and replace them with OPA2134s when you get some.

 

[music6000]

I always use Machined sockets on all my builds for Op Amps.
I try to buy from reputable sources but recently I got fake JRC4558D's.
I knew it as soon as they arrived but it would be a Pain if they were soldered in!

 

[xefned]

I imagine the benefits of low-noise OPA2134s will be wiped out by the noise of the PT2399s, but I don't really know.

 

[giovanni]

I imagine the benefits of low-noise OPA2134s will be wiped out by the noise of the PT2399s, but I don't really know.

That’s a good point. It is quite noisy. The Sonomatic sounds pretty quiet in the demos I have seen tho.

 

[spi]

I've used TL072 for the OPA2134 in my Magnetron. Am I missing out on high fidelity? I don't know because I almost always use dirt.

 

[Feral Feline]

Since PT2399s are noisy, all the more reason to keep the rest of the circuit as quiet as possible.

Even if you use dirt most of the time, those few times where you need a really clean sound with delay...


It's like a food recipe where you use only the freshest ingredients and then skimp by using canned stewed tomatoes...?

Make things as tasty as possible!

 

[Cybercow]

That’s a good point. It is quite noisy. The Sonomatic sounds pretty quiet in the demos I have seen tho.

The one I've built is pretty quiet as well. I also incorporated the mods from the Sonomatic Echo-Swell Mod update. (attached)

 

[giovanni]

The one I've built is pretty quiet as well. I also incorporated the mods from the Sonomatic Echo-Swell Mod update. (attached)

View attachment 75619 View attachment 75620

Did you try a TL072 in place of the OPA2134? I would be curious how much IC choice affects the noise floor.

 

[Cybercow]

Did you try a TL072 in place of the OPA2134? I would be curious how much IC choice affects the noise floor.

No, I did not. I was more focused on getting the Echo-Swell mod right.

Like I and others have mentioned, socket & see. It can't hurt. And when you get an OPA2134 you swap it to see.

 

[zgrav]

The one I've built is pretty quiet as well. I also incorporated the mods from the Sonomatic Echo-Swell Mod update. (attached)

View attachment 75619 View attachment 75620

same here. quiet build using those mods. there is a lot of variation in how quiet or noisy the PT2399 chips can be. probably a good idea to use sockets and then try swapping out the delay chips to find the quietest ones.

 

[giovanni]

Turns out I do have some OPA2134 that I bought a while ago. So I can A/B test. I’ll report what I hear.