Search found 212 matches

by Frank_NH
18 Apr 2019, 12:42
Forum: Boutique Stompboxes dissected...
Topic: Analogman - King of Tone [traced]
Replies: 465
Views: 239794

Re: Analogman - King of Tone [traced]

Hi Manfred, I also have the MA856 and MA858 data sheets, and also one for the BAS33, and I went ahead and plotted the curves with my 1N4148 and BA100 data on a semi-log plot (the plot format used in the datasheets). The plot is attached. Note that the datasheet curves are the performance @25C and re...
by Frank_NH
17 Apr 2019, 15:44
Forum: Boutique Stompboxes dissected...
Topic: Analogman - King of Tone [traced]
Replies: 465
Views: 239794

Re: Analogman - King of Tone [traced]

I used a clean 9V power source (not a battery) and arranged a simple circuit on my breadboard with a potentiometer in series with a 1k (1%) metal film resistor and the diode. Varied the pot to provide a range of currents. Measured the voltage drop across the resistor to get the current and the volta...
by Frank_NH
17 Apr 2019, 13:25
Forum: Boutique Stompboxes dissected...
Topic: Analogman - King of Tone [traced]
Replies: 465
Views: 239794

Re: Analogman - King of Tone [traced]

I took some data last night using my DVM for a plain 1N4148 and the BA100 that I have. I plotted the data in Excel (see attachment) - there's definitely a difference. Also the DVM on its diode setting indicates a difference in forward voltage. One more thing - after doing a little more research, the...
by Frank_NH
16 Apr 2019, 17:25
Forum: Boutique Stompboxes dissected...
Topic: Analogman - King of Tone [traced]
Replies: 465
Views: 239794

Re: Analogman - King of Tone [traced]

Thanks Manfred - very interesting. The BA100 curve looks almost identical to your previous 1N4148 curve. My DVM shows my BA100's FV to be in the 0.7 - 0.75V range, with 1N4148 being about 0.6 - 0.65V. I suppose there can be some variability between specific batches of diodes. Still, I would recommen...
by Frank_NH
15 Apr 2019, 13:45
Forum: Boutique Stompboxes dissected...
Topic: Analogman - King of Tone [traced]
Replies: 465
Views: 239794

Re: Analogman - King of Tone [traced]

I've been playing around with a blues breaker circuit on my breadboard, and one diode I think may make a good substitute for the KOT MA856 is the BA100. Has a Fv ~ 0.7 V and is a silicon signal diode. They're not too common, but are available from some suppliers. Thanks for the hint. I just ordered...
by Frank_NH
15 Apr 2019, 04:26
Forum: Boutique Stompboxes dissected...
Topic: Analogman - King of Tone [traced]
Replies: 465
Views: 239794

Re: Analogman - King of Tone [traced]

I've been playing around with a blues breaker circuit on my breadboard, and one diode I think may make a good substitute for the KOT MA856 is the BA100. Has a Fv ~ 0.7 V and is a silicon signal diode. They're not too common, but are available from some suppliers.
by Frank_NH
27 Feb 2019, 16:13
Forum: Modern Stompbox Effects (1975 - ...)
Topic: Op Amp Theory
Replies: 5
Views: 2185

Re: Op Amp Theory

And don't forget the "glitch" associated with response of some op amps when they hit the rails...(via mictester) " I also avoid the use of some op-amps in feedback clipper circuits - many types tend to "glitch" when switching gains as the diodes go into conduction, which add...
by Frank_NH
23 Feb 2019, 02:01
Forum: Modern Stompbox Effects (1975 - ...)
Topic: BBE - Acoustimax [schematic]
Replies: 14
Views: 7680

Re: BBE - Acoustimax [schematic]

The gain feedback resistor R14 seems too small. And what’s with those weird values? Anyhow try 22k - that should give you some gain.
by Frank_NH
22 Feb 2019, 17:37
Forum: Modern Stompbox Effects (1975 - ...)
Topic: BBE - Acoustimax [schematic]
Replies: 14
Views: 7680

Re: BBE - Acoustimax [schematic]

It looks like it uses a bipolar power supply (+/- 12V ?). Other than that, doesn't appear be overly complicated.
by Frank_NH
18 Feb 2019, 00:44
Forum: Boutique Stompboxes dissected...
Topic: J. Rockett Archer IKON gold
Replies: 13
Views: 5014

Re: J. Rockett Archer IKON gold

Well, if you want a different take on the Klon, here is a link to a vero layout of my Unicorn Overdrive. It’s a mashup of the Klon circuit with the Cornish buffer. It uses a bipolar supply for the op amp stages, giving it more than enough headroom. And it sounds so good that it’s earned a place on m...
by Frank_NH
15 Feb 2019, 15:05
Forum: Boutique Stompboxes dissected...
Topic: J. Rockett Archer IKON gold
Replies: 13
Views: 5014

Re: J. Rockett Archer IKON gold

Hey all, I have an Archer ikon torn down on my bench so thought I'd ask if there's any interest in some quality gut shots for a possible trace? AFAIK it may be an exact klon copy but I hafta say it sounds pretty nice even compared to a couple other klones I've come across. It's mostly SMD with a fe...
by Frank_NH
26 Jun 2018, 04:24
Forum: Boutique Stompboxes dissected...
Topic: Ctech - Sonny Boy
Replies: 20
Views: 9156

Re: Ctech - Sonny Boy

drbob1 wrote:Promise I'll get to the cap values!

I've never even heard of the Red Rooster! I wonder how many of those they made?
Looks like the Red Rooster was the Rock version of the Sonny Boy... 8)

http://www.effectsdatabase.com/model/ct ... r#pictures
by Frank_NH
19 Jun 2018, 02:51
Forum: Boutique Stompboxes dissected...
Topic: Ctech - Sonny Boy
Replies: 20
Views: 9156

Re: Ctech - Sonny Boy

Thanks Bajaman. OK, I get it now - odd Vbias arrangement, but it apparently works - current draw must be low. I also understand the switching, and I suppose you could use 4 SPST switches if you didn't want the complication of the rotary switch.
by Frank_NH
18 Jun 2018, 13:50
Forum: Boutique Stompboxes dissected...
Topic: Ctech - Sonny Boy
Replies: 20
Views: 9156

Re: Ctech - Sonny Boy

C-Tech Sonny Boy.GIF Here is a preliminary trace - just needs some capacitor values - or codes printed on them :wink: Also the diode values or codes :wink: cheers bajaman This looks cool 8) and something I would like to build on a vero layout. Bajaman - I think the rail for the IC non-inverting inp...
by Frank_NH
24 May 2018, 15:12
Forum: DIY Projects
Topic: German DIY distortion building instruction from 1985
Replies: 4
Views: 1892

Re: German DIY distortion building instruction from 1985

Yes, this looks very interesting! Wondering about the choice of frequency range for the mid-range filters, but I suppose you could tweak those if you wanted. Asymmetric hard clipping will probably sound pretty good here.
by Frank_NH
11 May 2018, 14:25
Forum: DIY Projects
Topic: BAJA Mars Hall 1959 plexi amp overdrive pedal 9v 090318 [documentation]
Replies: 38
Views: 13699

Re: BAJA Mars Hall 1959 plexi amp overdrive pedal 9v 090318 [documentation]

Hi Helge,

Unfortunately, this has been put on the back burner for now as my basement workshop space is being renovated and I have a bunch of other activities on my plate. Probably early June before I get back to it.

Frank
by Frank_NH
24 Apr 2018, 13:21
Forum: DIY Projects
Topic: BAJA Mars Hall 1959 plexi amp overdrive pedal 9v 090318 [documentation]
Replies: 38
Views: 13699

Re: BAJA Mars Hall 1959 plexi amp overdrive pedal 9v 090318 [documentation]

Last night, for fun, I created a simulation of the Bajaman 1959 amp sim in LTSpice and discovered two things that may be of interest: (1) The output level is on the low side with the master volume maxed, and you can increase the output level by substituting red LEDs for the 1N4148 diode pair before ...
by Frank_NH
23 Apr 2018, 13:30
Forum: DIY Projects
Topic: BAJA Mars Hall 1959 plexi amp overdrive pedal 9v 090318 [documentation]
Replies: 38
Views: 13699

Re: BAJA Mars Hall 1959 plexi amp overdrive pedal 9v 090318 [documentation]

Hi Helge, Thanks for the feedback. I realize now that I goofed in my recommendation, and that you should really use a cap and resistor in series, with the resistor sized based on the gain you want and the cap sized to give you the desired frequency response. However, there are some schematics that h...
by Frank_NH
18 Apr 2018, 18:17
Forum: DIY Projects
Topic: BAJA Mars Hall 1959 plexi amp overdrive pedal 9v 090318 [documentation]
Replies: 38
Views: 13699

Re: BAJA Mars Hall 1959 plexi amp overdrive pedal 9v 090318 [documentation]

Thanks for report. I was thinking you could, alternatively, make IC2a a gain stage, substituting a 22K resistor for the 2.7K in the feedback. As it is, it has a gain of only 2x - upping the feedback resistor would give you 10x. Looking at the original Marshall 1959 preamp schematic (link below), it ...