Apenas pueda ir a desarmar esa 1x12 le saco la foto.

Apart from that: I have a Marshall 6100, which I don't really play much and need money.
Any offer around here?.

Ok this evening I went and rebuilt this circuit and tried to add a load resistor (a mere 6.2 ohm) which didn't work

Raising the white flag I decided to take output voltage between the collector and collector resistor

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Basically if I add the load the resistor I get about 0.090 v across it

So idk how the heck I got sound out of the speaker

Then I noticed my voltages on the terminals of my transistor all drop a little when the input signal is added 
This probably is connected to the DC power supply being a ground for the signal 
Also I have some discrepancy between Vpp on the scope and Vrms on the meter despite doing the calibration 

So probably not much to be gained here but it's still been a good experience I have another book coming

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So hopefully I can start constructing some proven traditional configurations and attempt to comprehend them 

20 watts of solid state power, fed by a JFET preamp with 4 band EQ as well as a footswitchable volume (booster) and a "tubby" switch.  Sounds pretty good in the clips, but I'm not sure I'm 100% sold yet.  What do you think?

MSRP is $249 USD.

https://www.premierguitar.com/news/orange-amps-introduces-baby-terror

Yes sir thanks I'm definitely aware that some measurements need to be made and I'm actually dreading it because for me the going gets tough with using a multimeter when AC and DC are together.
That's why I like the scope it's kinda like flying VFR on a pretty day and then using the multimeter is like doing an instrument landing in fog   
But it's all stuff that I want to know how to do for instance I had taken the supply voltage DC reading and written it down but later when I disconnected the input I noticed it had dropped a few volts 

But yes thanks for your help 

Are you on battery?  Then it relies on the jack to turn on and you likely will have to replace the jack.  Have you tried with an AC adapter?  Some boss pedals won't show the light unless the exact model adapter is used.

Hfe of transistor in use is determined by circuit values.  The transistor datasheet value, or that shown on your peak atlas, must be at least that much or greater (for circuit to work right).
Kind of like how you have to use a resistor with a wattage value that will accommodate the wattage it will run at in circuit.
The waveform collapse when loaded shows you that you have voltage gain, but lack current drive.
Take your voltage you see unloaded, now calculate that across an 8 ohm load (or other load value).  What current do you calculate?  How about wattage?  Is this particular transistor capable of that? (see datasheet values)

This pedal had a crackling input jack which was switching off intermittently. Now it won't power on at all. I guess I should start at the input jack. Any other guidance? Schematic here https://pin.it/42edqg1Iv

Alright well back on my junk science project

I did get it to work after trying to up the base current then what really made a difference was bypassing the emitter resistor

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When I calculated Hfe I thought that sounded like a good round typical number 

But the peak atlas said much different 

So idk

Obviously I have much to learn here. 

One thing that was cool I managed to get a decent tone out of the output by connecting an 8 ohm speaker 🔊

But... whenever I connected the speaker the nice amplified output on the scope completely collapsed 

Also 50mv was about all I could get on the input before clipping

Seems like increasing DC did help obtain more output

So hey I'll take it 

Quote from: pontiacpete on September 08, 2026, 09:11:34 AMThanks for the info on compressors and IC5.
Back to the tracing thru this pre amp. I'm fumbling around here. This is what I'm finding at this point. The amp is passing a very low signal. When plugging into the 'power amp in' the signal seems to be normal for a return. But when sending the pre amp to another amp the signal is very weak. Plugging into the input it is also very weak and out to a speaker it is the same very weak signal.
I changed all 8 send and return jacks, they were very stiff and hard to plug into.
On IC401a pin 1 there is signal that is clear but not a whole lot of gain. I wish I could some post photos from my scope. Can some tell me how to do this?
On IC6b pin 7 and with compressor pot turned down there is a smaller clipped signal.

Hello sir
To post a pic go to "preview" and there should be a bar to add a pic thanks and good luck with your amp 

Thanks for the info on compressors and IC5.
Back to the tracing thru this pre amp. I'm fumbling around here. This is what I'm finding at this point. The amp is passing a very low signal. When plugging into the 'power amp in' the signal seems to be normal for a return. But when sending the pre amp to another amp the signal is very weak. Plugging into the input it is also very weak and out to a speaker it is the same very weak signal.
I changed all 8 send and return jacks, they were very stiff and hard to plug into.
On IC401a pin 1 there is signal that is clear but not a whole lot of gain. I wish I could some post photos from my scope. Can some tell me how to do this?
On IC6b pin 7 and with compressor pot turned down there is a smaller clipped signal.