Search found 263 matches

by alexradium
29 Mar 2021, 17:54
Forum: Amplifiers
Topic: schematic requiest BEL 1001 poweramp
Replies: 2
Views: 1070

Re: schematic requiest BEL 1001 poweramp

if it's not in the web,you can only get it from the factory. Anyway ,it's not that complex of an amp,judging by photos,generally speaking transistor power amps consist of 3 main topologies,once you figure out the design it's easy to understand what is working and what's not,and the schematic is almo...
by alexradium
06 Oct 2020, 18:56
Forum: Pedal Debugging & Troubleshooting Support
Topic: Lm13700 Small Stone depth mod
Replies: 13
Views: 3225

Re: Lm13700 Small Stone depth mod"

depth of what,which parameter,did you see it previously done?
by alexradium
30 Sep 2020, 17:44
Forum: Pedal Debugging & Troubleshooting Support
Topic: Ibanez WH10 calibration issue
Replies: 5
Views: 1212

Re: Ibanez WH10 calibration issue

Dbs are just a relationship between values, when measuring guitar circuits you use 100mV in input,in this case you should get 1V at output
by alexradium
30 Sep 2020, 15:48
Forum: Pedal Debugging & Troubleshooting Support
Topic: Ibanez WH10 calibration issue
Replies: 5
Views: 1212

Re: Ibanez WH10 calibration issue

you can't get 7,7 Vrms out of a 9V pedal,that's why you see a clipped signal. Your guitar can be anything up to 1V peak on the attack of the note,the average signal is obviuosly less than that. Opamp circuits output 6/7 volts peak to peak,unless you use special high quality chips Transistor buffers ...
by alexradium
09 Aug 2020, 09:54
Forum: Amplifiers
Topic: Amp switching
Replies: 6
Views: 1584

Re: Amp switching

i tell you this,i am restoring an old Binson hifi 60w,mid 60s amp,original tubes and caps,600V on plates and 390 on screens.
The one and only switch in this is a plastic case 1P1T,with copper tabs,so just one pole switching the main transformer on.
It works perfect like this,all these years.
by alexradium
31 Jul 2020, 05:32
Forum: Modern Stompbox Effects (1975 - ...)
Topic: EH pulsar tremolo,why 78l09?
Replies: 10
Views: 2783

EH pulsar tremolo,why 78l09?

I got this big box 3 knobs pulsar tremolo,on the box it's written 9vdc 100mA,ok, fine,but inside there was a 78l09 regulator between the DC Jack and the circuit,where also the 9v battery connects. Does it mean that EH power supplies were supposed to be 12v,or maybe 10 unregulated? Because it's clear...
by alexradium
17 Jul 2020, 14:49
Forum: DIY Projects
Topic: BAJA Sagittarian Charger (mini KLON) [documentation]
Replies: 515
Views: 133340

Re: BAJA Sagittarian Charger (mini KLON) [documentation]

germanium diodes doesn't matter how you put them once they are in antiparallel,same for 390n and 1k,no matter the position. you can debate on the positive signs of the zener and 4001,but i did this circuit long time ago,correct at first try,same for the pots,i don't have the original documents but i...
by alexradium
11 Jul 2020, 18:13
Forum: Pedal Debugging & Troubleshooting Support
Topic: Rangemaster weird voltages
Replies: 4
Views: 1323

Re: Rangemaster weird voltages

it looks inverted polarity
by alexradium
30 Jun 2020, 05:33
Forum: Boutique Stompboxes dissected...
Topic: Xotic - AC Booster [ goop-alarm ] [traced]
Replies: 129
Views: 56528

Re: Xotic - AC Booster [ goop-alarm ] [traced]

Typical soldering jockey mojo,like that 470 ohm cc resistor on output
by alexradium
21 Jun 2020, 09:33
Forum: Amplifiers
Topic: How to improve tube amplifier tone by changing one part
Replies: 101
Views: 29898

Re: How to improve tube amplifier tone by changing one part

if the sound changes with a perfectly clean signal through 2 specific different capacitors,then you have distortion,on one or both.
which should be measurable to a degree,especially with a 2 tone IMD test.
by alexradium
02 May 2020, 11:06
Forum: Pimp-My-Cheap-Pedal
Topic: Mosky Brown, a Pinnacle II clone
Replies: 10
Views: 6461

Re: Mosky Brown, a Pinnacle II clone

i'll tell you this,all those differences are just minor and those which count are basically in the biasing of the jfets,which was really specific in Wampler's case,he had them tested for the specific circuit and nobody knows the exact specs,plus he went through different layouts too,that makes a hig...
by alexradium
28 Apr 2020, 19:55
Forum: Pedal Debugging & Troubleshooting Support
Topic: Broken Dunlop 95Q... SMD help!
Replies: 12
Views: 2461

Re: Broken Dunlop 95Q... SMD help!

yes,there is a low temperature solder that helps,quick something.... or you can try carefully cut the legs of the chip and then remove the rest with the iron. or using one of those 100w "gun" irons,remove the original tip,and replace it with a copper wire shaped rectangular,the long sides ...
by alexradium
25 Apr 2020, 08:48
Forum: Pedal Debugging & Troubleshooting Support
Topic: Bench charge for pedal SMD repair??
Replies: 4
Views: 1629

Re: Bench charge for pedal SMD repair??

Thanks for the tip. I'll take a second look. The opamps looked in tact but maybe I missed it. I've read that reverse polarity usually takes out a diode or two near the power jack but they look fine. I do this as a hobby now (retired) so I won't charge much (maybe 12 pack of beer or toilet paper) if...
by alexradium
05 Mar 2020, 07:04
Forum: Software Room
Topic: Gaussmarkov Eagle and LTspice tutorials
Replies: 6
Views: 5358

Re: Gaussmarkov Eagle and LTspice tutorials

I could see some with way back machine
by alexradium
09 Jan 2020, 18:44
Forum: Amplifiers
Topic: Madamp M15MK1 build help....
Replies: 34
Views: 10709

Re: Amp build help....

insert the cap between the input jack tip and the joint of 1M and the 33k resistors
by alexradium
08 Jan 2020, 17:03
Forum: Amplifiers
Topic: Madamp M15MK1 build help....
Replies: 34
Views: 10709

Re: Amp build help....

i checked your schematic,and yes,its 123 to 133V on the first stages,that calls for dc leakage...
by alexradium
08 Jan 2020, 16:40
Forum: Amplifiers
Topic: Madamp M15MK1 build help....
Replies: 34
Views: 10709

Re: Amp build help....

Bumping my own thread! I managed to fix this amp eventually; after much checking and head scratching I could find no defective components or bad/incorrect connections. I negotiated a credit for another output transformer from the supplier. The amp now produces a rich and complex sound! One minor cr...
by alexradium
20 Dec 2019, 19:20
Forum: Boutique Stompboxes dissected...
Topic: Hermida Audio - Mosferato M2 (2004)
Replies: 5
Views: 1798

Re: Hermida Audio - Mosferato M2 (2004)

every time a solder jockey goops his clipping diodes,a honest engineer dies somewhere.
by alexradium
20 Dec 2019, 15:03
Forum: Boutique Stompboxes dissected...
Topic: Hermida Audio - Mosferato M2 (2004)
Replies: 5
Views: 1798

Re: Hermida Audio - Mosferato M2 (2004)

In the next James Bond movie he will try to catch the secret hidden underneath that goop,Her Majesty wants to know!
Happy Gooped Holydays!