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Re: Friedman BE-OD Pedal

PostPosted: 06 Sep 2017, 21:51
by J0K3RX
bancika wrote:Here's a very quick and messy demo of my build https://soundcloud.com/bancika/friedman ... quick-test

plugged into interface and added Bias Amp (plexi clean) and a touch of reverb. All controls at noon, both on the pedal and in the amp sim.

Cheers,
Bancika



Nice Lynch! What's it sound like running direct, no amp sim but just running into a vst cab sim with impulses?

Re: Friedman BE-OD Pedal

PostPosted: 06 Sep 2017, 22:51
by bancika
here's the same thing with impulse alone (no reverb either)...sounds better this way I think.

https://soundcloud.com/bancika/friedman ... to-impulse

Re: Friedman BE-OD Pedal

PostPosted: 08 Sep 2017, 19:49
by bancika
Got some time to experiment with the clipping section and replaced the 4 diodes with two ZTX transistors (and two jumpers to keep the signal flowing) and there's a dramatic change in noise. It wasn't particularly noisy before but now it's dead quiet, even on max gain. It did lose some of the sharpness, but I actually prefer it this way. Stock pedal doesn't sound very tube amp-like to me, it's a bit harsh. With ZTX there's plenty of bite left but it's a bit more manageable.

I left sockets for LED diodes as well, so I might experiment with them, maybe replace them with a germanium diode + a MOSFET to smooth up things even further.

Here's a quick clip with gain maxed.

https://soundcloud.com/bancika/friedman ... 1-max-gain

And one similar to previous ones

https://soundcloud.com/bancika/friedman ... e-w-ztx951

both are into clean plexi. I intentionally left some noise so you can hear how it performs.

Thanks to bajaman for the idea and for the transistors! :applause:

Re: Friedman BE-OD Pedal

PostPosted: 09 Sep 2017, 10:58
by bancika
One more update - experimented with replacing LED clippers. Started with LED 3 and 4 after U2.2, as those were glowing brighter when playing compared the the other two...I'm assuming those are clipping the signal harder and playing with them would have a bigger impact. So I replaced them with a BS250 MOSFET (wired as S -> D+G) in series with a germanium diode to polarize it. The MOSFET has a forward voltage drop around 1.9V (0.6V in the opposite direction from the internal diode), so combined with a Ge diode, it comes up to around 2.1V. Red LEDs I have drop around 2V, so the clipping threshold is not all that different, but MOSFET clips very differently compared to the LED. LED has some hard, harsh quality to it that I don't particularly enjoy, especially with two LED clippers in the circuit :) MOSFET brought the distortion level down a little bit (which is not necessarily bad) reduced the buzzy overtones and made it a little bit more amp like.

Listening soundcloud clips back, there's no that much difference between them but in real life I can definitely hear the difference. So far, this combination of clippers sounds the best to me. LED in the first stage, ZTX in the second and MOSFET+Ge in the 3rd stage.

Here's the same clip played with ZTX and MOSFET clipping installed

https://soundcloud.com/bancika/friedman ... x951-and-1

and with gain maxed

https://soundcloud.com/bancika/friedman ... x951-and-2

and the same thing with the pedal running at 12V. It a little bit less compressed, but not night and day

https://soundcloud.com/bancika/sets/fri ... e-od-clone

Re: Friedman BE-OD Pedal

PostPosted: 09 Sep 2017, 12:39
by bajaman
Hi bancika,
did you just use the one BS250 and germanium diode or a pair in parallel reversed ?

Re: Friedman BE-OD Pedal

PostPosted: 09 Sep 2017, 13:03
by bancika
It's a pair of mosfet+diode, one instead of each LED
Cheers

Re: Friedman BE-OD Pedal

PostPosted: 09 Sep 2017, 18:07
by J0K3RX
Oh boy, lookie what I stumbled upon today... Friedman Dirty Shirley pedal

http://friedmanamplification.com/friedman-pedals/dirty-shirley-pedal


Link

Re: Friedman BE-OD Pedal

PostPosted: 09 Sep 2017, 19:04
by andlord
Oh boy...I bet it is a smd-fest again. Sounds damn fine

Re: Friedman BE-OD Pedal

PostPosted: 10 Sep 2017, 14:12
by Ice-9
andlord wrote:Oh boy...I bet it is a smd-fest again. Sounds damn fine


Well at least that makes it so much easier to trace. :wink:

Re: Friedman BE-OD Pedal

PostPosted: 10 Sep 2017, 16:51
by Groovenut
Ice-9 wrote:
andlord wrote:Oh boy...I bet it is a smd-fest again. Sounds damn fine


Well at least that makes it so much easier to trace. :wink:

Imma bet it's just a modified BE-OD. Switch instead of a pot on the Tight control and an added mid control. IMO, the delay in release was because of a manufacturing issue, so it will be interesting to see if the layout is the same as the BE-OD.

Re: Friedman BE-OD Pedal

PostPosted: 10 Sep 2017, 18:14
by andlord
Wouldn't be new for Friedman. As far as I see it all the 100w heads are on the same pcb with a few tweaks here and there.

Re: Friedman BE-OD Pedal

PostPosted: 11 Sep 2017, 21:33
by bancika
@bajaman

did you experiment with one diode + the ZTX in series instead of two diodes? I measured the ZTX and forward voltage is about the same as silicon diodes (~620mV), so if we use only one pair of ZTX devices, we'll effectively halve the headroom compared to the stock circuit. I tried the combination of Si diode and ZTX today and it's about halfway between the two versions...not bad at all.

Cheers

Re: Friedman BE-OD Pedal

PostPosted: 11 Sep 2017, 23:16
by bajaman
@bancika
No, i had not tried that but I just ran a sim with a 1N4148 in series with ZTX951 and it showed the same response as two 1N4148. The sim for two ZTX951 in series shows a slight +2db broad boost around 600Hz however. I will give some of your suggested mods a try.
cheers
bajaman

Re: Friedman BE-OD Pedal

PostPosted: 12 Sep 2017, 04:36
by HamishR
I built my second BE-OD last week with Bugg's PCB. This time I left the second pair of LEDs out as per Bajaman's suggestion and I find the reduction in dirt to be quite noticeable. There is still plenty though! Actually it's an interesting sound because it's less harsh now. I also used silver mica for the pF values, and used a 470pF instead of the 120. My first pedal I also used 470pF but in ceramic, and used the full complement of LEDs. It's dirtier and a touch harsher.

I may stick some 1N4148s where the LEDs were left out as I usually have good results with them. I suspect LEDs were originally chosen because they seem to have that smooth, buttery sound that so many like - I generally prefer the spikier sound of 4148s.

FWIW I tested both pedals with gain on full and the trimmer up full - I'm not getting any oscillation with either. And I can't see why anyone would want to use the pedal like that - it's, um, not very subtle! You get a super-distorted sound way before you get to full. I keep the trimmer on lowest. Way more gain still than I ever need!

Re: Friedman BE-OD Pedal

PostPosted: 12 Sep 2017, 06:56
by bajaman
I keep the trimmer on lowest. Way more gain still than I ever need!

The trimmer is a very useful way to balance the ratio of clipping diodes (or ZTX transistors etc) in the feedback loop and the reversed pair of parallel red leds following this stage.
With the trimmer set to lowest you should hear more "dirt' from the diode / transistors and less from the red leds and with it set to full the red leds will saturate well before the feedback diode stage.
i suspect that it was friedman 's intention to adjust this trimmer to set this ratio of feedback to shunt clipping for the most realistic amp sound :wink:
cheers
bajaman

Re: Friedman BE-OD Pedal

PostPosted: 12 Sep 2017, 21:35
by bmxguitarsbmx
BMX two op version of Friedman BE-OD.pdf
I also keep the trimmer gain at the lowest. Since, at this setting, the gain of this stage is -1, we can eliminate it. For educational purposes, let's also (properly) remove the op-amp that creates the active Vref supply and and only use the capacitively filtered resistive divider:

The Be-ODD Junior?

Re: Friedman BE-OD Pedal

PostPosted: 13 Sep 2017, 22:23
by bancika
HamishR wrote: I suspect LEDs were originally chosen because they seem to have that smooth, buttery sound that so many like - I generally prefer the spikier sound of 4148s.


I find them to be quite the opposite. LEDs sound harsher to me than any other diodes. YMMV

Re: Friedman BE-OD Pedal

PostPosted: 14 Sep 2017, 20:45
by temol
Here's my version of the BE-OD. Bugg's PCB inside.

Image

T.

Re: Friedman BE-OD Pedal

PostPosted: 15 Sep 2017, 12:35
by HamishR
Hey Bancika - really? I guess I've only ever tried LEDs where they have been chosen for their reduced high end or whatever it is that makes them sound like they do. It's really interesting how different diodes can sound - it's actually quite subtle but to us tone geeks they really make a difference.

Have to say I'm generally not a huge fan of LED clipping. It seems a bit too unsubtle or something - 1N4148s can at least sound a bit clearer. But I do play at the lower gain end of the spectrum.

Re: Friedman BE-OD Pedal

PostPosted: 16 Sep 2017, 06:23
by guiltyspark
J0K3RX wrote:Pink Eye is what you get when you play with a Brown Eye and forget to wash yer hands and then rub your eyes :blackeye Also referred to as Sphinc Eye or Stink Eye...

And then there are some that like both flavors :|
2 in the pink...... and 1 in the stink :lol:
[ Image ]


My inner 14 year old thinks this pic is fuckin' hilarious! :thumbsup