Boss SD1 *the other bleed*

[Chaoticidal]

Hey duders I still have the pedal. I put it in a box 3 years ago. As it turns out, I have a new amp that loves it just the way it is. With the typical gain down/level up setting in front of my Marshall JMD:1 (DSL channel), it sounds great. When I switch to a clean channel it still sounds great. Also take out the LED/volume mod, or adjust the number of LEDs. Too much headroom allowing too much dry signal through? Anyway the LEDs sound better hanging off a cactus.

[Killthepopular]

Something just occurred to me. Because it wasn't clear which way round the LEDs are supposed to go I just stuck em in without thinking about it. As i replaced 2 LEDs, the likelihood of me putting them both in the right way round is 1/4, so at the moment the clipping circuit on my pedal is probably reacting as if i had simply removed one or both of my diodes. I suspect I'm hearing just distortion from the opamp rather than from the LEDs, which is why it sounds so hard. Also the LEDs were barely lighting up when i smacked the strings. I'll try again with the LEDs and see how that sounds. I suspect I'll get less of the clean bleed.


Maybe one diode was put in the right way round and one not, so one half of the wave is getting massively clipped and compressed and the other half is just this super loud uncompressed sound...

[Ben N]

Also I've struggled to find many resources on what dirt pedals work well with clean SS amps. It seems like, 1. 99% of pedals are designed to be used in front of a broken up tube amp and 2. Most guys who own loads of pedals also mostly use tube amps so can't offer much insight on the topic.

Well, you are in the right place--because building pedals from the ground up is a great way to match your needs. You are certainly right about the SD-1. As noted above, a sort of blending is really endemic to it, and as noted just about everywhere, it (like all TS types and similar mid-boosting overdrives and dirty boosts) is really best suited to boosting a tube amp. Which is why I think you are trying to turn a llama into a dog. You might even succeed, but there are much better ways to get there.
You might want to take a look at the "amp simulator" designs at runoffgroove.com, such as Professor Tweed, Supreaux Deux, Azabache, Britannia and Thor. My understanding is that they are meant to function more as a standalone preamp than an additional gain/eq stage, and work well with a clean SS amp. As an added bonus, because they do not share the non-inverting opamp signal path of the TS types, they also don't have that peculiar "blending" effect.

[Killthepopular]

Turns out I'd put one LED in the wrong way round. Have removed it and swapped it round. Now both LEDs light up. Still sounds about the same though. Lots of gain, little distortion and lots of clean bleed.

[Killthepopular]

I think you are trying to turn a llama into a dog. You might even succeed, but there are much better ways to get there.
You might want to take a look at the "amp simulator" designs at runoffgroove.com, such as Professor Tweed, Supreaux Deux, Azabache, Britannia and Thor. My understanding is that they are meant to function more as a standalone preamp than an additional gain/eq stage, and work well with a clean SS amp.

Depends on what you mean by "better". If you mean "better result" then you're probably right. But if you mean "less time/effort and less cost" then i imagine you would be wrong.

Thanks for the link. I am tempted to build my own pedal, although pedal building becomes its own kind of rabbit hole which i don't want to fall down too far. I'll consider it.

I'll probably just stick the stock silicon diodes back in, i suspect this will lessen the bleed issue as it didn't really bother me back in the stock version of the pedal. OTOH i'd still like to try a hard clipping mod, if anyone is forthcoming with some advice on the matter.

[Chaoticidal]

Turns out I'd put one LED in the wrong way round. Have removed it and swapped it round. Now both LEDs light up. Still sounds about the same though. Lots of gain, little distortion and lots of clean bleed.

Yeah man that's why I pulled the LED mod. When I first started this post I had forgotten that I'd even done the LED. If there is any dry bleed through now it's not enough to notice, so like I said earlier the LED sounds better hanging off a cactus lol

[Killthepopular]

(http://www.hobby-hour.com/electronics/s/sd1-super-overdrive.php) C4 is connected between Vref and the 10k resistor following the gain stage. You can remove the diodes from the feedback loop completely and reattach them across C4 instead.

Actually i think maybe i understand this now. I already removed C4 as part of my general tinkering with the filters in the pedal. Does this mean i could connect two diodes in parallel (in opposite directions) and just solder that into where C4 used to be and then i would have a hard clipping circuit?