Search found 1702 matches

by Manfred
18 Mar 2024, 17:47
Forum: Pedal Debugging & Troubleshooting Support
Topic: 6N17B not working [SOLVED]
Replies: 13
Views: 8509

Re: 6N17B not working [SOLVED]

heater.jpg
heater.jpg (15.1 KiB) Viewed 3468 times
by Manfred
17 Mar 2024, 10:04
Forum: Pedal Debugging & Troubleshooting Support
Topic: 6N17B not working [SOLVED]
Replies: 13
Views: 8509

Re: 6N17B not working [SOLVED]

For how many tubes do you need the heating voltage generation?
by Manfred
16 Mar 2024, 09:18
Forum: Pedal Debugging & Troubleshooting Support
Topic: 6N17B not working [SOLVED]
Replies: 13
Views: 8509

Re: 6N17B not working [SOLVED]

In my opinion, this mosfet voltage regulator circuit is not suitable for a small voltage difference between input and output.
by Manfred
15 Mar 2024, 14:55
Forum: Pedal Debugging & Troubleshooting Support
Topic: 6N17B not working [SOLVED]
Replies: 13
Views: 8509

Re: 6N17B not working [SOLVED]

The link is to a picture of the step-up regulator.
What is the circuit of the voltage regulator for the heaters?
Please attach a sketch of the schematic.
by Manfred
14 Mar 2024, 21:26
Forum: Pedal Debugging & Troubleshooting Support
Topic: 6N17B not working [SOLVED]
Replies: 13
Views: 8509

Re: 6N17B not working [SOLVED]

The picture of the voltage regulator doesn't help much to find out anything.
Do you have more information about it, perhaps the circuit diagram?
What is the input voltage of the regulator?
Does the input voltage remain the same under load or does it drop?
by Manfred
11 Mar 2024, 20:18
Forum: Pedal Debugging & Troubleshooting Support
Topic: 6N17B not working [SOLVED]
Replies: 13
Views: 8509

Re: 6N17B not working [SOLVED]

Edit: Values corrected

First stage 5E3 using 6N17B:
5E3-1 6N17B.jpg
by Manfred
10 Mar 2024, 11:09
Forum: Pedal Debugging & Troubleshooting Support
Topic: 6N17B not working [SOLVED]
Replies: 13
Views: 8509

Re: 6N17B not working [SOLVED]

The circuit with the 6N17B tube requires an adjustment of the components for the operating point setting as the values or the characteristic curves are very different to the 12AX7 (7025) tube.
The Fender circuit cannot simply be adopted.
See for example here:
sub-mini 5E3.png
by Manfred
20 Feb 2024, 20:00
Forum: Pedal Debugging & Troubleshooting Support
Topic: Dunlop Cry baby JH-1 low headroom [SOLVED]
Replies: 8
Views: 14713

Re: Dunlop Cry baby JH-1 low headroom [SOLVED]

You have replaced both transistors with 2N5088 types. That was wrong, because according to the original circuit diagram, the first transistor is an MPSA13, which is a Darlington transistor. I have made another circuit simulation to see more precisely. The clipping of the sinusoidal signal always occ...
by Manfred
20 Feb 2024, 12:54
Forum: Pedal Debugging & Troubleshooting Support
Topic: Dunlop Cry baby JH-1 low headroom [SOLVED]
Replies: 8
Views: 14713

Re: Dunlop Cry baby JH-1 low headroom [SOLVED]

I ran a circuit simulation and found that the shape of the output signal started to round off at about 1.3 Vpeak.
This happens at certain frequencies depending on the potentiometer setting.
Does your guitar have a pickup with a high output level?
by Manfred
11 Feb 2024, 10:40
Forum: Pedal Debugging & Troubleshooting Support
Topic: Boss PH1r
Replies: 4
Views: 500

Re: Boss PH1r

Connect drain-source from Q6 and see if the phaser signal then comes out.
by Manfred
09 Feb 2024, 22:56
Forum: DIY Projects
Topic: OGBip-2 overdrive on 2n5088 bipolar transistor
Replies: 11
Views: 844

Re: OGBip-2 overdrive on 2n5088 bipolar transistor

Thanks for sharing, I like the sounds. :thumbsup
by Manfred
22 Jan 2024, 19:00
Forum: Pedal Debugging & Troubleshooting Support
Topic: charge pump voltage divider issues?
Replies: 5
Views: 645

Re: charge pump voltage divider issues?

Insert a 7809 voltage regulator with the usual parts around between the plug-in power supply connection and your circuit.
by Manfred
18 Jan 2024, 21:34
Forum: Pedal Debugging & Troubleshooting Support
Topic: Rat - high pitched squeal
Replies: 4
Views: 686

Re: Rat - high pitched squeal

Some op-amps tend to oscillate with a larger capacitive load.
Try the in-loop compensation from this article.
https://www.analog.com/en/analog-dialog ... er-25.html
by Manfred
07 Jan 2024, 11:29
Forum: Amplifiers
Topic: Fender H.O.T. practice amp hum (50hz) noise even the guitar is un plugged.
Replies: 20
Views: 3110

Re: Fender H.O.T. practice amp hum (50hz) noise even the guitar is un plugged.

Thank you George for your hints, I will try this out on the next amplifier with a hum problem.
Peavey Bandit Detail.jpg
by Manfred
06 Jan 2024, 21:21
Forum: PCB Guitar Mania - pedal builders group and debug
Topic: Maximum Crank no effect sound
Replies: 9
Views: 1922

Re: Maximum Crank no effect sound

Is the 3PDT switch soldered in twisted?
by Manfred
30 Nov 2023, 16:29
Forum: DIY Projects
Topic: Tetrafuzz
Replies: 7
Views: 3287

Re: Tetrafuzz

Great development, sounds good to me ! :thumbsup
by Manfred
23 Nov 2023, 22:17
Forum: Parts & Tools Sourcing & Trading
Topic: *best* LDR for Mutron III / Neutron circuit
Replies: 40
Views: 33488

Re: *best* LDR for Mutron III / Neutron circuit

I assume that by omitting the first two letters before 1558 in the schematic, Musitronics had the option to install the Omp amps depending on market availability.
There were LM1558, MC1558, CA1558 and perhaps other designators.
by Manfred
23 Nov 2023, 09:04
Forum: Parts & Tools Sourcing & Trading
Topic: *best* LDR for Mutron III / Neutron circuit
Replies: 40
Views: 33488

Re: *best* LDR for Mutron III / Neutron circuit

In the factory schematic, all OP amps are specified as 1558. The Mutron on my bench shows two RC4558BP and one RC4558BN. Since the device works, I leave this in its original state so as not to reduce the value. Yes, in some modifications the lower noise NE5532 are recommended for the signal path to ...
by Manfred
20 Nov 2023, 22:43
Forum: Parts & Tools Sourcing & Trading
Topic: *best* LDR for Mutron III / Neutron circuit
Replies: 40
Views: 33488

Re: *best* LDR for Mutron III / Neutron circuit

I created this Mutron III PCB clone for troubleshooting. I took the component identifiers and the values from the factory circuit diagram. It was an unexpected fault, part of a trace under A5&A5 was oxidized away. Probably battery acid from a leaking battery, there was also a small oxidized area...