Type: Posts; User: vintagekiki; Keyword(s):
Something's is irregular with your computer.
On initial tests shown in your video1) (0:05) all pots are at min (0) and you have a small buzz on (both ch) the amplifier.
This test indicates that the cause of the buzz is not in the preamp but already occurs after IC3b (pin 7)
Clean ch has a buzz because it has a "large" C6 capacitor (22u), the drive ch has a "small"...
Check voltage at Speaker Output (J5); The voltage must be 0 VDC
Is it crappy sound on both channels or just one?
First test the PA, put the guitar in the power amp in (J6).
If the clear sound the...
Mostly copy / paste of the same schematics all over the web
Splawn Fans Forum
Easy, easy pace.
Just so you know the forum has not forgotten you.
Look at the pictures
Soldering probably doesn't look jubilee after 10-20 years.
Two weeks the thread is inactive.
Does this mean that the FSR has been repaired, and run around the stage.
Since with the new V3 the symptoms are still the same, most probably some of the output tube (V4-V7)
To find out freely remove all output tubes, and put in the same socket one by one tubes.
F2 (0.5A) fuse must be slow (T) not fast (F).
If F2 (0.5A) fuse blows when STANDBY (SW2) is OFF check / replace D5-D9 (1N4007), C27 (47u/450V), and eventually C42 (.1/1000V).
Schematics from prowessamplifiers.com is wrong, NFB from OT (point F) connected over 100k to gnd; presence control shown in the wrong place ... ...
In the original Redbear used in preamp 6n2p...
Remove fixed presence C70 (.68)
If you find Aphex 106 Easy Rider schematics, be kind and share it (upload) with the music-electronics-forum.
Thanks in advance.
Same story turns around and we are still at the beginning. I've listened to the youtube video several times , and the amount buzz seems pretty normal to me.
The shortest way is to compare your FM25...
Voltages is OK.
Set all volume and tone controls to "zero", all switches to "off" and put guitar cable in Guitar input jack (JK1)
What is voltage on both sides of R1 (10k)?
When input jack (JK1)...
R160 (2k2) and C41 (.1uF) located in the NFB circuit (R102; C64) and form a fixed presence boost that is controlled by R160 (2k2).
Carefully decrease R160 gives more presence boost. If you are not...
- Do you have sound when you plug guitar in FX RET (JK3)?
- Check fuse F1; F2 (T2A)
- Do you have voltage at test point TP11 (+12.6V); TP12 (-12.6V); TP9 (+3.3V)
If on the TP (9; 11; 12) some test...
What happens when Q2 is removed and the correct Q1 is in place.
When using Gain select (S1) Footswitch (J2) must be disconnected.
Q1 and Q2 form switch drive or normal ch, them operated by U5b (half 4560) which receives command from Footswitch (J2) or Gain select (S1)
Depending on the choice J2 or S1, the voltage on pin 7...