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Messages - Jazz P Bass

Pages: [1] 2 3 ... 15
1
Amplifier Discussion / Re: Peak dissipation in class B output stage
« on: Today at 05:02:18 PM »
The output transistors that you picked are way overkill for the amp that you are designing.
Yeah, they will work.
But still.
Way over the top.

2
Amplifier Discussion / Re: Peavey VSS-20 amplifier with chorus noise problem
« on: September 27, 2020, 10:13:08 PM »
Have you checked the 'digital +9vdc supply'?
It should be pretty free of any ripple voltage (Vac).

3
Amplifier Discussion / Re: Peak dissipation in class B output stage
« on: September 22, 2020, 11:43:35 AM »
I would build a tried & true amplifier.
Attached is a simple low power amplifier.
Tube Works TD 742.
Build it.
Study it.
Blow it up.  :lmao:

4
The Newcomer's Forum / Re: Roland JC-120 with weak reverb
« on: September 19, 2020, 12:45:40 AM »
A TA-7200 P 10 watt power amplifier is used to drive the reverb pan.
It appears to be a 1.1 Vac output signal on the schematic.
Measure it and see what you have.

5
Schematics and Layouts / Re: G-K Gallien-Krueger MB112 ICEpower
« on: August 29, 2020, 11:57:36 AM »
ICE Power schematics have never been released as far as I know.

6
Tubes and Hybrids / Re: Blackstar HT5 noisy Clean channel
« on: August 16, 2020, 01:19:15 PM »
I have attached the input circuit diagram.
The signal branches off of IC2A to the Clean and the Crunch channel.
Either of those is selected by jfets. (Clean/ Fet1: Crunch/ Fet2)
You will need to track down where in the Clean circuit the signal is failing.


7
Guitar News / Re: Quilter OverDrive 202 - palm sized amp with rock concert sound
« on: August 13, 2020, 01:14:32 AM »
" switchmode amplifier, PWM (pulse width modulated) amplifier and Class-D amplifier"

8
Amplifier Discussion / Re: peavey musician series 400
« on: August 08, 2020, 01:09:50 AM »
!!!"  DISCONNECT any speaker"!!!

9
The Newcomer's Forum / Re: FX loop noise
« on: August 06, 2020, 11:43:38 AM »
Try the guitar into the Zoom & then go into the FX Return jack.
This will tell if it is a Send circuit issue or a Return circuit issue.
Be aware that you may have to adjust the gain on some of the Zoom presets.

10
Amplifier Discussion / Re: Crate G130C Amp
« on: July 24, 2020, 12:51:35 AM »
To answer the posts question, here is a crop of the power amp board locating D16 (+16Vdc) and D17 (-16Vdc)

11
Amplifier Discussion / Re: Crate G130C Amp
« on: July 23, 2020, 11:51:25 AM »
Piease post the relevant schematic.
You really should test the power supply before assuming the failure mode is the exact same.

12
Amplifier Discussion / Re: LabSeries L11 power section repairs & spares
« on: July 20, 2020, 03:11:23 PM »
http://www.rru.com/~meo/Guitar/Amps/Lab/schem.html

13
The Newcomer's Forum / Re: Marshall Valvestate 8080 power Amp repair.
« on: July 19, 2020, 09:08:26 PM »
-7Vdc on the speaker out connection indicates a failed output section.
The lower minus part is turned on when it should not be.
Do not hook up the speaker until this is resolved.

14
The Newcomer's Forum / Re: Greetings! Looking to fix up a Marshall G30RCD
« on: July 11, 2020, 12:05:53 PM »
You will have to remove the old solder from the PCB before you install the new jack.
You will need a solder sucker,
Or 'solder braid'.

15
Amplifier Discussion / Re: Peavy 130 Special needs some TLC
« on: July 10, 2020, 12:09:48 PM »
Here is the schematic.

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