Here is a good ol’ Rat that I’ve had in non-working condition. I managed to fix it this morning, it was quite easy (one resistor to replace in the power supply circuitry).
Also I added a 3-positions switch that allows to change the clipping mode :
stock silicon diodes
red LEDs (like ok the Turbo Rat)
no clipping at all
My prefered tone is most probably with the red LEDs, which brings some kind of nice articulated grit in the high frequencies. The mode with no clipping is very close. The stock diodes are more mellow. That said, all modes sound really like a Rat, no big surprise.
Well, used to own one - didn’t quite gell with it… Too many patches on there that I really didn’t care for. Also, some limitations in terms of which and how many effects I could have at the same time (typically, those I liked would have to go on the same button ). And, finally, I didn’t find the sound quality sufficient (for what I wanted to have).
It certainly is an interesting multi-effects box, just not for me
Meanwhile I am running in to a lot of circuits I am looking at with electrolytic caps in the signal path and it messes with me every time until I realize that in all of these there is also a big DC bias across them too, holding down their polarity. In fact I think some of them are there simply to remove that DC offset, though still unsure why they would choose electrolytics by choice.
Yeah it’s mostly to remove the DC offset, when a big value is needed regarding to the wanted/needed bandwith, this cap being also a low-pass filter. Nowadays there are very good electrolytic audio capacitors, that do not sound crappy at all.
To get a low cutoff frequency, you need big caps. Electrolytics are basically your only choice unless you want to spend huge amounts of space and $$. And good electrolytics sound just fine, so there is no real problem to using them. They are polarized but the voltages that are going across them are small enough that it doesn’t matter.
Sure. Well I guess even one volt antibias can pop an electrolytic in a lot of cases, but generally the magic here is that there is a bias across them already (in the case I was looking at, ~9v) and the AC component is a +/- 0.5v signal oscillating on top of that, so it works fine.
Absolutely true - and most good circuit designs will have that bias. For years I did audio circuit designs, but they were either integrated circuits (can’t do an electrolytic on an IC!) or extremely high end systems and we didn’t worry so much about the $$, but I often slapped together quick systems with electrolytics in the audio path because that’s what I had in the drawer, and I didn’t worry about a volt of AC across the cap. The fun thing was putting them in switched AC sockets so when a tech would come in and turn on their bench they’d get a surprise. We did stupid things when we were young…
lol yes. Like showing off shorting the big ones with a screwdriver and then freaking because it got welded to the cap and the shop teacher was walking over
the harmonic booster seems to always be the forgotten red headed stepchild of the lineup. does it deserve the ultra treatment? dg thinks so. it is interesting.
). And, finally, I didn’t find the sound quality sufficient (for what I wanted to have).
