Alritey let’s continue details of my TTSH with two spring reverb modifications. If you’re looking for other build / modification posts on the project, please visit the main page right here.
This modification is done to improve the noise floor of spring reverb, by upgrading the opamp in the output amplifier circuit (recovery amp). The mod was suggested by user Nordcore at Muffwiggler forum and looks like this:
I sort of failed with adding this mod in that I didn’t bother taking before and after audio recordings: So it’s rather impossible to say how much the noise floor was effectively reduced. On my TTSH the circuit was noisy before and is noisy after.. Yet I’d still say it’s better.
On to the build..:
Heyyy I’m once again catching up my TTSH build documentation with yet another modification. Yayyyy!
This mod is based on Altitude909’s add-on board, which adds a Arp Odyssey style hard sync between oscillators. The build has been well-documented in this thread @ Muffwiggler, so please check there if you’re planning to add one to your TTSH (Hi Vlado!). I did a slightly alternate version for myself and on this post we’ll look at that instead! But first, here’s a video by Stephen Drake on what hard synced oscillators sound..:
If you’re all new into how analog synthesizers can be controlled, you may first want to take a look at this Wiki article on CV/Gate for some jargon busting. Other than that, let’s dive right in.
Among the first electronics mod I wanted to add to my TTSH was the Gate Booster. To fully open the ADSR envelope generator of TTSH a +10VDC gate needs to be applied, thus in it’s stock config the envelope can’t be fired properly by using eg. any external gear that outputs a +5V gate. Add to the common CV/Gate specs, the TTSH envelope generator also needs a trigger signal (very short pulse) to work properly. This can be used to restart the envelope without disabling gate signal.
So what the Gate Booster does is, it converts low voltage level gate signals to higher voltage and generates the trigger signal from the gate input. The particular circuit board I bought for myself is this modified version (sold by Oshpark) with a socket for a Midimplant MIDI-to-CV/Gate converter board. Having MIDI (keyboard) input just made so much more sense than eg. building a CV keyboard like the Arp 3620.
This was a quick “let’s see what happens” kind of mod for my TTSH.
In their stock config, the TTSH loudspeakers are supposed to be fastened to the circuit board, which is then fastened to the front plate. Handy approach eg. for having the electronics as a entirely separate, single ‘module’ for servicing etc. But problem with this is that it leaves a ~12mm gap between the driver and the front panel. Read More…
Alright on to some finished surfaces with the TTSH build.. This entry is all about tolex, from someone with zero previous experience on applying / handling technique. If you ended up here looking for some kind of advice, this may (or may not) be a good read. You’ve been warned! :)
Do also check out what has happened in this project previously, links are at the bottom.