Messages

Hello,

Yes, I had the back cover on. 

It works now. After replacing Q4-Q10 with 2N3904s, everything is running smoothly. What I don't understand is why the Harbinger 1.5 and even 2.0 still use 2N5088s. Maybe I got a bad batch, but they were definitely the cause. According to the transistor tester, they're all fine. Annoying, because the device would have worked from the start...

Anyway, never mind, now I have a working device.

Thanks for your thoughts and contributions.

Holger

That's great Holger!

Reading this makes me want to go back to my Harbinger 1.5... I wonder if my cheap 5088s are the problems. That poor thing has been in an esd bag for years now 

Give it a try, maybe we can help.

Assuming you put the back cover on... haha ...  yeah I think replacing the remaining 2N5088s with 2N3904s would be a good idea.

Huh, I don't know.

Yeah, you could try replacing Q2 and Q3.

Hi Holger,

You mentioned you've replaced 3 transistors, what transistors did you have in there before?

Is it possible Q2 and Q3 need to be replaced?

It seems like every time you replace a transistor, there is an improvement.

Can you post some pics?

What voltages are you getting on Q1?

Huh, I thought they'd retired and rode off into the sunset...

Awesome. Gotta like a pedal with a Throb toggle!

There's your band name, Throb Toggle.

Hahaha!!

Awesome. Gotta like a pedal with a Throb toggle!

How about this:

https://www.allaboutcircuits.com/video-tutorials/op-amps-low-pass-and-high-pass-active-filters/

http://sim.okawa-denshi.jp/en/OPseikiLowkeisan.htm
http://sim.okawa-denshi.jp/en/OPseikiHikeisan.htm

Does anyone know how to bias a Tone Bender mk1? I have mine set to chinese democracy but it's not working.

Here's a pic of the circuit:

I can see them, those are fantastic! Thanks for posting.

Hmm...

What voltages do you have on the transistor?

Maybe something wrong with the pot?

That finish looks fantastic! Sounds great, too.

It only has 4 resistors, one is 390k, (could that be the one?)

Is that actually a 390R coming off of the emitter?

So:

910k voltage divider resistor, between base and v+
100k voltage divider resistor, between base and ground
10k  collector resistor, between collector and v+
390R emitter resistor, between emitter and ground

Like mauman said, the 910k and the 10k should connect to v+

The weather here in Sacramento has been really nice this summer. It's supposed to be 79f/26c today, well below average. And it's been like this for a couple of weeks now, and before that it wasn't bad. I'm really happy with it, I don't do well in the heat.