BossAreaForum

Wow, very cool! I've often thought about getting an old tube tester, but wouldn't know which makes and models are considered good, and what options are needed. Size would be a consideration too. And there's calibration challenges too, I'd imagine? I'd only need one for the typical 6l6, el84, 6v6, an...

Maybe this will help? Features: RES:（resonant）- to simulate resonant response in different environment of acoustics. CFR（center frequency）- to adjust centre frequency of format. LPF（low pass filter）- to adjust the radio-frequency component of reverb response. PRD（pre-delay）- to simulate the delay o...

Maybe this will help? Features: RES:（resonant）- to simulate resonant response in different environment of acoustics. CFR（center frequency）- to adjust centre frequency of format. LPF（low pass filter）- to adjust the radio-frequency component of reverb response. PRD（pre-delay）- to simulate the delay of...

Is there much of a difference between the 1981 circuit (A) compared to the (B)? Thanks. Let's play Where's Waldo (Wally at some places)? :lol: Here is a side by side picture of my earliest version "A" (0300 FEB 1981) and "B" (126000 NOV 1981). The only difference I found is at the lower left corner...

Oh man, sorry to hear that!

You saw one eh?

I'd love to have an all original silver screw SD-1. However, the one in the 1st post here is clearly a fake!

The case maybe original, (batch 0300) but the circuit is from a later SD-1...

Great photo comparison Old_Iron!

It's also fantastic to see a 0300 silver screw on the inside! Thanks for posting these.

Did the SD-1 get anymore revisions over the years? (C, D, E, etc )

I don't know if this is the right thread to post in, but here goes: I just opened up my old beat-up May 1982 SD-1 to see what's under the hood. It looks like I have the JRC 4558D chip with the black stripe/ band clipping diodes. Sounds great! 8-) It's the 1st revision to the circuit. (B) Is there mu...