Search found 101 matches

by ebuprofen
12 Sep 2015, 15:05
Forum: Stuff Seen for Sale
Topic: FS: Poltava fuzz/wah/tremolo vintage soviet guitar effect [sold]
Replies: 1
Views: 4399

FS: Poltava fuzz/wah/tremolo vintage soviet guitar effect [sold]

For sale rare vintage effect pedal made in 1981 in Soviet Union with fuzz, wah and tremolo effects. In great working order, although potentiometers could be replaced, but i thought that original ones would maintain it's originality (but can be replaced for new ones if desired). Jacks were modified t...
by ebuprofen
28 Jul 2015, 08:04
Forum: Amplifiers
Topic: Bass tube amp not loud enough
Replies: 38
Views: 17598

Re: Bass tube amp not loud enough

well, already tested in the customer studio and it is fine, i guess my cheap soldering iron was giving that squeal or something in my apartment. Now only the old trafo buzz is present but it is not disturbing for customer.
Once again, thank you everyone for help!
Case closed :D
by ebuprofen
13 Jul 2015, 11:52
Forum: Amplifiers
Topic: Bass tube amp not loud enough
Replies: 38
Views: 17598

Re: Bass tube amp not loud enough

well, as i resoldered fx loop like this one https://smg.photobucket.com/user/broper63/media/FXLOOP-1.jpg.html the amp is louder but also i get a high pitch squeal, not very loud, but irritating, when not playing bass. when i touch fx loop tube or second tube in preamp i get hum as i touch input of t...
by ebuprofen
12 Jul 2015, 09:48
Forum: Amplifiers
Topic: Bass tube amp not loud enough
Replies: 38
Views: 17598

Re: Bass tube amp not loud enough

ok, now it is loud with the second stage of the fx loop as simple gain stage, not cathode follower, but now it is also noisy. when i touch second and third lamp with my finger, i get hum like i am touching the input with my finger, so i guess it is the wire problems, as not all of them in preamp i d...
by ebuprofen
11 Jul 2015, 16:43
Forum: Amplifiers
Topic: Bass tube amp not loud enough
Replies: 38
Views: 17598

Re: Bass tube amp not loud enough

ok, as i checked the other half of the ampeg schematic, the original driver has 5.5v on first stage and 30v on output stage, that goes to power tubes, so my ~3vac are 10 times lower, my driver is too weak
by ebuprofen
11 Jul 2015, 15:23
Forum: Amplifiers
Topic: Bass tube amp not loud enough
Replies: 38
Views: 17598

Re: Bass tube amp not loud enough

didn't get my 300w resistor, but manage to find 12x47ohm20w resistors in local store and got 4.2 ohm and 240w in parallel connection. i notice that on preamp schematic there are voltages shown for signal, 15mV in, 0.9v stage1, 7v stage2, 8v stage3 and 0.4v stage4 gain was at max, tonestack center po...
by ebuprofen
09 Jul 2015, 05:09
Forum: Amplifiers
Topic: Bass tube amp not loud enough
Replies: 38
Views: 17598

Re: Bass tube amp not loud enough

you got it a bit wrong :)

0.065vac to PI (PhaseInverter/Driver, right?) and 0.49vac at speaker out and 7,54 is how many times output is greater than input, so it is 7,54 times greater (0,49/0,065=7,54)

and fx loop was out of the circuit, when i did the measurements
by ebuprofen
08 Jul 2015, 16:50
Forum: Amplifiers
Topic: Bass tube amp not loud enough
Replies: 38
Views: 17598

Re: Bass tube amp not loud enough

okay, as i am still waiting for my power resistor to arrive, i've made some "quiet" measurements my DMM is a http://www.peaktech.de/productdetail/kategorie/digital---handmultimeter/produkt/p-3340.html gave 100Hz signal from PC soundcard 0.065vac to PI input gave me 0.49vac on amps output, ...
by ebuprofen
07 Jul 2015, 19:15
Forum: Amplifiers
Topic: Bass tube amp not loud enough
Replies: 38
Views: 17598

Re: Bass tube amp not loud enough

ok, a tried a bit with live sine wave, that is to speaker, not the resistor i am still waiting. a have a question about how to measure, since AC signal wave measuring is not very common for me. i have to measure it like average DC, common VM pin on amps ground and red pin to stage output? but have t...
by ebuprofen
07 Jul 2015, 09:33
Forum: Amplifiers
Topic: Bass tube amp not loud enough
Replies: 38
Views: 17598

Re: Bass tube amp not loud enough

thank you all for your help, guys! the fx loop is taken from Weber kits and should work as buffers, it was strange for me too, that second half is also cathode follower, but didn't worry about that i think i did try it with bypassed fx loop and had no major difference when i plugged my active K5 bas...
by ebuprofen
06 Jul 2015, 16:21
Forum: Amplifiers
Topic: Bass tube amp not loud enough
Replies: 38
Views: 17598

Re: Bass tube amp not loud enough

wow, thanks a lot, enorbet2, for your post. so, you suggesting, if i have no scope, to have signal generator (no keyboard, but maybe a PC audio card output with constant signal from some audio software) and power resistor (about 200w?) and also for you all to know, i have very small experience with ...
by ebuprofen
05 Jul 2015, 19:19
Forum: Amplifiers
Topic: Bass tube amp not loud enough
Replies: 38
Views: 17598

Re: Bass tube amp not loud enough

tried swapping preamp and PI tubes, nothing happened, only small difference when changing 12au7 in fx loop to 12ax7. if i connect bass in return input of the fx loop, should i get very loud bass sound or not? because i am not getting it, it is like bedroom level in return jack i will check cathode v...
by ebuprofen
05 Jul 2015, 18:30
Forum: Amplifiers
Topic: Bass tube amp not loud enough
Replies: 38
Views: 17598

Re: Bass tube amp not loud enough

no red plating, they are set at 35mA, wich is quite cold, if i put them about 58mA, no difference in sound and no red plating

power supply is like this one but with more filtering for preamp stages

http://www.chambonino.com/work/hiwatt/hw4u.jpg
by ebuprofen
05 Jul 2015, 15:59
Forum: Amplifiers
Topic: Bass tube amp not loud enough
Replies: 38
Views: 17598

Re: Bass tube amp not loud enough

Okey, then i guess i have to work with the wiring first

this is my output stage

Image
by ebuprofen
04 Jul 2015, 09:01
Forum: Amplifiers
Topic: Bass tube amp not loud enough
Replies: 38
Views: 17598

Re: Bass tube amp not loud enough

deltafred wrote:Have you had a scope on it to make sure it is not oscillating at a frequency above the speaker/audio range?
unfortunately, don't have one
by ebuprofen
02 Jul 2015, 19:19
Forum: Amplifiers
Topic: Bass tube amp not loud enough
Replies: 38
Views: 17598

Re: Bass tube amp not loud enough

My first thought would be what is the power handling capability of the power transformer? Can it support the added current of the two added power tubes? Can the 6.3V winding support two more filaments? Sometimes transformers are designed to tight tolerances as needed for a particular design. I have...
by ebuprofen
02 Jul 2015, 15:26
Forum: Amplifiers
Topic: Bass tube amp not loud enough
Replies: 38
Views: 17598

Bass tube amp not loud enough

Hello, everybody I have rebuild a tube bass amp with 6xKT88, added a FX Loop and simplified the preamp (midrange control) and for some reason, tube amp with 6xKT88 isn't loud enough, at max Gain and Master settings it isn't loud enough even for rehearsals, almost like bedroom level. the problem is n...
by ebuprofen
10 Feb 2013, 12:19
Forum: Pimp-My-Cheap-Pedal
Topic: BBE boosta grande
Replies: 3
Views: 3362

Re: BBE boosta grande

found one pic on the net :D
by ebuprofen
16 Jan 2013, 07:27
Forum: DIY Projects
Topic: Baja Trembulator schematic, board layout and circuit board [documentation]
Replies: 166
Views: 53582

Re: Baja Trembulator schematic, board layout and circuit boa [documentation]

omg, galmar, thanks a lot, one coupling cap didn't make any difference, but two of them (the second one is between DEPTH pot and inverting input of the second half of TL062) made the pedal work as it should, thanks again, you saved my ass :D moderators, please remove two schematics that I posted abo...