Darlington pair RM ??

[LightSoundGeometry]

http://diy.smallbearelec.com/HowTos/BreadboardGeDarlingtonRMs/BreadboardGeDarlingtonRMs.htm

I might have missed but I think Bear says either pnp or npn works, but my question is the grounding? I am using two PNP but I have set my circuit up as the Bear does n his tutorial - and thank you so much for the well presented and easy to follow how to a darlington pair.

ground as normal for an RM?

[antonis]

You should reverse the "polarity" of your p-n-p pair..

Q2 Emitter to +9V (actually to 10k resistor) & Collectors to GND (actually to 3k9)

[LightSoundGeometry]

You should reverse the "polarity" of your p-n-p pair..

Q2 Emitter to +9V (actually to 10k resistor) & Collectors to GND (actually to 3k9)

I got her and she sounds incredible ..unbelievable ....this is where the beef is at




un freaking real ...the best sounding circuit I have ever played ..im blown away

[thermionix]

I built a Darlington RM to make use of some low gain Ge PNPs I had.  I didn't do the OhMyDarlington, just a standard RM, positive ground, with the darlington pair in place of the single transistor.  It works, it sounds cool.  I don't know how "correct" it sounds, because I've never played another RM.

It's kind of "quacky" sounding, and gets loud as hell.  Apartment living prevents me from using it as it should be, but I did get a chance to try it into a cranked amp at the LGS.  Pretty classic.  At some point I'll probably upgrade to a "proper" single transistor from Small Bear.  Would just drop in, I built it with an eyelet board.

[smallbearelec]

http://diy.smallbearelec.com/HowTos/BreadboardGeDarlingtonRMs/BreadboardGeDarlingtonRMs.htm

I am glad that you are happy. Treat a PNP Darlington pair just as you would a single PNP device...ground is positive, and the power supply issue(s) are the same as for the PNP RM. If you want a negative-ground version that uses cheep devices, Sziklai is the way to go.

[duck_arse]

LSG - share your beef. can you post your transistor voltages, pleeze?

[LightSoundGeometry]

LSG - share your beef. can you post your transistor voltages, pleeze?

Vc = Q1 is 7.4 and Q2 is 1.6 vdc

got some 60 x 60 Pad-Per-Hole Perfboard  from the bear and will try to transfer this onto perf this weekend.

[thermionix]

Funny..."REAL 1984 Wendy's ad"...as if we don't all remember.  Wendy's was actually pretty tasty back in the 70s/80s.  Dog food now.

Don't know if you have the capability to upload a sound or video clip, but I'd like to hear your RM when you have it up and running.  See how mine stacks up.  I'm particularly interested in the low volume (~unity) sound, because that's about all I get much chance to try with mine, and all the YouTube videos I've seen of others are with them cranked.

[LightSoundGeometry]

Funny..."REAL 1984 Wendy's ad"...as if we don't all remember.  Wendy's was actually pretty tasty back in the 70s/80s.  Dog food now.

Don't know if you have the capability to upload a sound or video clip, but I'd like to hear your RM when you have it up and running.  See how mine stacks up.  I'm particularly interested in the low volume (~unity) sound, because that's about all I get much chance to try with mine, and all the YouTube videos I've seen of others are with them cranked.

she is on perf now and is seeing about 8 volts but sound crazy freaking good and I will get s clip up soon


video uploading .still needs pull down R and now the LED is out ..I might of measured wrong R because its on but barely ..so I might have to replace LED or D1 R

its a beast ..my goodness

* pulled out the R and it ws 470K not 47 lol .., heck with it ..I am sticking a low one on and let her shine bright screw the battery life

*  added a 1 meg pull down on input for the popping

[LightSoundGeometry]

"I'd like to hear your RM when you have it up and running" - sound demo below, I love it

[thermionix]

Sounds good!  Strat?  Pretty different from mine, but kind of apples and oranges.  If you look at the OhMyDarlington, mine doesn't have Rc or Rd.  Just a straight darlington pair in place of the OC44.  Also my output cap is .01, which I think is the original Dallas value.  Don't know how much difference that makes.

The transistors I used were an AC128 with an Hfe of maybe 20 (forget the leakage) and an NTE126A with an Hfe of about 6, no leakage.  The AC128 is "first" in the pair.  I could probably mess around and get a better sound, but I'm really more inclined to just order a good OC44 or OC71 from Small Bear and call it a day.