SR&D upgrade to reduce or eliminate hiss?

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X100Ver10
Posts: 86
Joined: Mon Sep 18, 2017 2:49 pm

SR&D upgrade to reduce or eliminate hiss?

Post by X100Ver10 » Tue Nov 06, 2018 4:13 pm

Has anyone heard of SR&D (back in the day) offering to do an upgrade to their headphone amps to help reduce or eliminate hissing? If so, do you know what they did?

Someone is telling me that SR&D used to offer this upgrade in the past if you sent them your headphone amp. Since they all seem to have some hiss, especially the Soloist, I'm curious what the upgrade consisted of. Thanks.

RockmanCentralBob
Posts: 251
Joined: Fri Feb 06, 2015 2:10 am

Re: SR&D upgrade to reduce or eliminate hiss?

Post by RockmanCentralBob » Fri Nov 09, 2018 6:32 pm

I haven't heard of that for the headphone amps, but I know the XPRa had many changes to improve the s/n ratio. The Rev 20 Sustainor is also very quiet.

If it's really an issue, I think you can look into swapping out the op amps for low noise models, but better know what you are doing.

X100Ver10
Posts: 86
Joined: Mon Sep 18, 2017 2:49 pm

Re: SR&D upgrade to reduce or eliminate hiss?

Post by X100Ver10 » Sat Nov 10, 2018 4:57 pm

Thanks Bob. I had never heard of that either. I talked to the guy a little bit more. He had an original Rockman headphone amp that was noisy (I assumed hissing because he was asking me about the hissing from a Soloist I was selling). He contacted SR&D in the past and they said they would do an upgrade for a small fee if he sent it to them. He decided not to and actually threw it in the garbage. :shock: He probably just had some loose solder joint(s) at one or more of the jacks. I would imagine SR&D was probably just going to put the latest version circuit board in it for him or resolder the jacks.

When you say op amps, are you talking about the 2 LM386n-1 IC's or a different IC? I'm just curious. If SR&D could never figure out the noisy headphone amps, I never will either.

RockmanCentralBob
Posts: 251
Joined: Fri Feb 06, 2015 2:10 am

Re: SR&D upgrade to reduce or eliminate hiss?

Post by RockmanCentralBob » Mon Nov 12, 2018 12:09 am

X100Ver10 wrote:
Sat Nov 10, 2018 4:57 pm
When you say op amps, are you talking about the 2 LM386n-1 IC's or a different IC? I'm just curious. If SR&D could never figure out the noisy headphone amps, I never will either.
I thought they were TL072's, but I haven't opened one up in a long time.

Honestly, I'm really not sure that they are THAT noisy or that it can't be controlled through EQ'ing or noise gates.
Recall that these little headphone amps found their way into pretty much every major studio in the 80's and were used on countless productions for bands and commercials alike. You might be overly concerned about something if you are playing with it alone vs recording it and putting it in a mix. My guess is that in a mix, you aren't going to hear it that much, especially if you use any kind of noise gating.

X100Ver10
Posts: 86
Joined: Mon Sep 18, 2017 2:49 pm

Re: SR&D upgrade to reduce or eliminate hiss?

Post by X100Ver10 » Fri Nov 16, 2018 4:31 pm

Thanks again Bob. I personally don't think the hissing is an issue. You only hear it when not playing anyway. It certainly isn't enough of an issue to try and find replacements for those IC's.

RockmanCentralBob
Posts: 251
Joined: Fri Feb 06, 2015 2:10 am

Re: SR&D upgrade to reduce or eliminate hiss?

Post by RockmanCentralBob » Sun Nov 18, 2018 2:19 pm

X100Ver10 wrote:
Fri Nov 16, 2018 4:31 pm
I personally don't think the hissing is an issue. You only hear it when not playing anyway.
Exactly, and that's why we have noise gates to take care of that.