Author Topic: Rusty Box/Traynor TS50B - are these caps backwards? + any tips  (Read 26897 times)

MrStab

Re: Rusty Box/Traynor TS50B - are these caps backwards? + any tips
« Reply #80 on: September 12, 2013, 12:10:52 PM »
i took the charge pump out of the equation altogether, i think my camera's just a bit misleading with the LED brightness. i'm using 1K resistors (one via. Millennium Bypass) - i did some testing with the circuit load hooked up and it seemed like the right balance for this one. i went with red for lowest current consumption.

weirdly, since boxing, interference seems to have gone. i say "weirdly" because it's just unusual in my experience with RF/external interference. i straightened out the knobs a bit:



it's for my singer's bro-in-law, so worst-case scenario it's not an outright witch hunt if he doesn't like it. lol
(i was only recently informed that imgur is a hive of adolescent tomfoolery, but i'm too deep into the habit now)
« Last Edit: September 12, 2013, 12:54:36 PM by MrStab »

psychedelicfish

Re: Rusty Box/Traynor TS50B - are these caps backwards? + any tips
« Reply #81 on: September 13, 2013, 06:18:05 PM »
Looks nice! Any chance of a sound sample?
If at first you don't succeed... use bigger transistors!

duck_arse

Re: Rusty Box/Traynor TS50B - are these caps backwards? + any tips
« Reply #82 on: September 14, 2013, 11:35:39 AM »
why wouldn't he like it? it's got knobs, switches, lights, shiny bright metal  .....
"awww, pass up the hatchet baby - uhh!"

MrStab

Re: Rusty Box/Traynor TS50B - are these caps backwards? + any tips
« Reply #83 on: September 14, 2013, 12:35:15 PM »
here's a coupla clips on a shit cam, with the pedal going into the front of the amp. i didn't think to record when actually trying it as a preamp. well, going straight through my amp's FX return at least - is a bit more defined that way, but the MG's preamp doesn't adulterate it too much.

please excuse the shitty improv, quality, the fact i'm using a guitar/amp and not a bass, and (what i hope was) hot glue residue which was since cleaned off. lol


MrStab

Re: Rusty Box/Traynor TS50B - are these caps backwards? + any tips
« Reply #84 on: September 14, 2013, 02:58:31 PM »
the dude just came  over and tried it into the Aux input on a Cube 30 Bass amp - much more beef. success!

jordan s

Re: Rusty Box/Traynor TS50B - are these caps backwards? + any tips
« Reply #85 on: March 07, 2014, 03:19:46 PM »
I wanted to say that I built this using the most recent strip board layout, mostly with spare parts I had laying around. I did need to use shielded cable for the input and jumper and change the value of C2 to get the noise down to a useable level. I'm using a 12V DC wall wart with a 6v regulator for vbias. So far, sounds awesome. We'll see how she teams up with my 1400 watt power amp tonight.


rankot

Re: Rusty Box/Traynor TS50B - are these caps backwards? + any tips
« Reply #86 on: April 10, 2020, 12:50:47 PM »
I've built this using schematic from this thread and my own PCB layout. It works fine, but it's a little bit too noisy. I use 350kHz charge pump to provide 15V from standard 9VDC, but noise is audible and this charge pump is almost noiseless, so I presume it's not the source of the noise. [edit: I tried to decouple V+ & V- to ground with 10u capacitors and noise level does change, so it seems that my charge pump is also pumping the noise. I will investigate this further.]

However, I noticed that another version of this preamp - found in Traynor TS120B, have two differences compared to this on (Traynor TS50B, actually):
  • Gain pot is A100k instead of A1M;
  • There's a 47p capacitor parallel to gain pot.

So I tried to add that cap and the huge amount of noise is gone. What I want to ask is: is it normal for such a circuit to be noisy, as it has really big amplification factor, or there's something else I should try to fix?

I used TL071, BC550C (don't have MPSA18) and BC640 instead of MPS8599 (similar characteristic). Maybe those BC640 are wrong choice? Some good info could also be found here: https://www.diystompboxes.com/smfforum/index.php?topic=110526.msg1014149#msg1014149
« Last Edit: April 10, 2020, 02:15:50 PM by rankot »
50 pedals and counting!

rankot

Re: Rusty Box/Traynor TS50B - are these caps backwards? + any tips
« Reply #87 on: April 18, 2020, 03:53:55 PM »
So I tested this with normal 15V PS (regulated with linear regulators), which is quite quiet :)

Guess what? The noise level of Traynor preamp is the same as with SMPS.

It could be nice to test this with some other kind of transistors, maybe those BC640 I picked are too noisy? The trouble is they use ECB pinout, instead of usual CBE/EBC :(
50 pedals and counting!