Search found 82 matches

by guiddruid
09 Nov 2009, 23:16
Forum: Boutique Stompboxes dissected...
Topic: WMD Geiger Counter - [gut shots]
Replies: 139
Views: 31193

Re: WMD Geiger Counter - [gut shots]

1/ microcontroller code; trivial. Would be interesting to know what cpu is used. (DAC topology is not obvious from the limited info so far, for example. Nor is sample rate control.) 2/ look up tables; approximating them would be not too hard. bit for bit exact copies would require some code (or lots...
by guiddruid
09 Nov 2009, 08:18
Forum: Boutique Stompboxes dissected...
Topic: Pete Cornish Tube Buffer
Replies: 20
Views: 6843

Re: Pete Cornish Tube Buffer

1M/20pF is the sort of thing you would find marked on an ancient oscilloscope input or probe (both impedances are to gnd - thee 20pF is a parasitic capacitance, not a physical component). Perhaps _that's_ the type of app note the circuit was copied from?
by guiddruid
07 Nov 2009, 16:27
Forum: Modern Stompbox Effects (1975 - ...)
Topic: EHX - Voice Box
Replies: 0
Views: 1099

EHX - Voice Box

Found this via google; http://www.flickr.com/photos/smilinggoat/3227940280/sizes/l/ "All new toys must be promptly taken apart" - quite right, and photographed, and posted on the web. Like the way it's made, with the snap-out sub circuits. I think they've done a great job with their new die-cast box...
by guiddruid
07 Nov 2009, 09:37
Forum: Modern Stompbox Effects (1975 - ...)
Topic: EHX - Memory Boy
Replies: 46
Views: 20976

Re: EH Memory Boy

cool. U7 looks like it needs seating down in its socket properly. wonder why they have used sockets though...
by guiddruid
06 Nov 2009, 22:54
Forum: Stuff Seen for Sale
Topic: Unmarked MXR phase 90 (script?) [sold]
Replies: 7
Views: 5828

Re: Unmarked MXR phase 90 (script?) [sold]

the markings on the script pedals was done with rub-down lettering (read that in an interview with the owner in the analog man book). not very robust, I would guess, and that pedal looks like it's seen a few knocks.
by guiddruid
06 Nov 2009, 16:14
Forum: Boutique Stompboxes dissected...
Topic: Pete Cornish Tube Buffer
Replies: 20
Views: 6843

Re: Pete Cornish Tube Buffer

and for schems of every conceivable Hiwatt input stage; http://mhuss.com/Hiwatt/tech2.html
by guiddruid
04 Nov 2009, 14:28
Forum: Boutique Stompboxes dissected...
Topic: Toneczar - Openhaus [traced]
Replies: 365
Views: 120624

Re: Toneczar Openhaus [gutshots and schematic] [traced]

oooh, show us a picture, go on :wink:
by guiddruid
04 Nov 2009, 14:03
Forum: Boutique Stompboxes dissected...
Topic: Zvex - Probe series
Replies: 413
Views: 90304

Re: Zvex - Probe series

or use an LED, an LDR and a simple shutter, like in a Morley wah... more reliable, fewer electronic components... and probably off topic - sorry :oops:
by guiddruid
03 Nov 2009, 23:00
Forum: Boutique Stompboxes dissected...
Topic: Toneczar - Openhaus [traced]
Replies: 365
Views: 120624

Re: Toneczar Openhaus [gutshots and schematic] [traced]

the electronic measurements but the analyzer wont be giving you part numbers I dont believe. BTW — there were many silicon transistors that came in TO5 cases in the early days as well. Yes, you are quite right - we will know a lot more about this particular pedal than we would ever have known from ...
by guiddruid
03 Nov 2009, 19:41
Forum: Boutique Stompboxes dissected...
Topic: Toneczar - Openhaus [traced]
Replies: 365
Views: 120624

Re: Toneczar Openhaus [gutshots and schematic] [traced]

Back on topic; wonder what a SiGe transistor would sound like?
hfe is over 300 on this one... price is about 1US$;
http://www.nxp.com/#/pip/pip=[pip=BFU725F_1]|pp=[t=pip,i=BFU725F_1]
https://gb.mouser.com/ProductDetail/NXP/ ... wuLg%3d%3d
by guiddruid
03 Nov 2009, 12:19
Forum: Boutique Stompboxes dissected...
Topic: Himmelstrutz - Fetto [traced]
Replies: 141
Views: 46108

Re: Himmelstrutz - Fetto [gut shots] [traced]

looks like RTV, or silicone sealant http://tiny.cc/sealant
by guiddruid
01 Nov 2009, 19:16
Forum: Boutique Stompboxes dissected...
Topic: Toneczar - Openhaus [traced]
Replies: 365
Views: 120624

Re: Toneczar Openhaus [gutshots and schematic] [traced]

alpha have some; http://www.alphapotentiometers.net/html/9mm_pot_13.html http://www.alphapotentiometers.net/html/16mm_pot_21.html no idea if these are any good (not even sure if the 9mm parts are really dual gang - looks like one pin too few), but I am sure there must be _some_ good quality pots of ...
by guiddruid
01 Nov 2009, 11:09
Forum: Boutique Stompboxes dissected...
Topic: Toneczar - Openhaus [traced]
Replies: 365
Views: 120624

Re: Toneczar Openhaus [gutshots and schematic] [traced]

2007 version is slightly different then; extra pole on the mode switch, to halve the value of R37 in crunch mode (giving a bit more treble?). Any other changes? Saruman, did you measure Q3 and Q4, or are the Hfe values an educated guess? Any idea what the two plated holes marked "1" & "2" are for? D...
by guiddruid
31 Oct 2009, 10:16
Forum: Boutique Stompboxes dissected...
Topic: Toneczar - Openhaus [traced]
Replies: 365
Views: 120624

Re: Toneczar Openhaus [gutshots and schematic] [traced]

Sold! Just ordered one.... thanks for the help. Cool! That's dedication... should be no mystery at all about suitable transistors :D You will need to disconnect at least 2 of the pins of the transistors to measure them correctly. Don't forget you don't necessarily need to remove the transistor from...
by guiddruid
30 Oct 2009, 11:44
Forum: Boutique Stompboxes dissected...
Topic: Toneczar - Openhaus [traced]
Replies: 365
Views: 120624

Re: Toneczar Openhaus [gutshots and schematic] [traced]

Link missing from pins 4&2 of the expression pedal? :) Also guess that the LED is connected off-PCB to R18? Much easier to read now, thank you. Any chance you could add the component values to the schem? It makes it easier to read, imho. Seems a little odd to me that the transistor (distortion?) sta...
by guiddruid
29 Oct 2009, 12:49
Forum: Boutique Stompboxes dissected...
Topic: Toneczar - Openhaus [traced]
Replies: 365
Views: 120624

Re: Toneczar Openhaus [gutshots and schematic] [traced]

Q1 looks likely to be a linear regulator, not a transistor. Probably 15v? If you use your meter on diode mode, you should be able to identify the base of each transistor. B-E and B-C should both measure as diodes, polarity of the diodes will tell you if you have a PNP or NPN. Forward voltage will te...
by guiddruid
21 Oct 2009, 10:43
Forum: Boutique Stompboxes dissected...
Topic: Effectrode - Tube Vibe
Replies: 116
Views: 23966

Re: Tube-Vibe

This is the suspected microcontroller: http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010277 Once we have figured out which pins of this chip go where, it shouldn't be too hard to write some code which will work in a _similar_ fashion. To get it _very_ close to the original will probab...
by guiddruid
19 Oct 2009, 20:09
Forum: Boutique Stompboxes dissected...
Topic: WMD Geiger Counter - [gut shots]
Replies: 139
Views: 31193

Re: WMD Geiger Counter - [gut shots]

Lots of choices for the uC, like you say. I think, however, that the device here is a QFP, not an 8pin DIL/SOIC; http://www.freestompboxes.org/viewtopic.php?f=7&t=6865&start=20#p75724 I would also be surprised to see a PIC; the quoted figures for sample rates don't match with the available periphera...
by guiddruid
19 Oct 2009, 12:10
Forum: Boutique Stompboxes dissected...
Topic: Krank - Distortus Maximus [traced]
Replies: 87
Views: 30076

Re: Krank - Distortus Maximus [traced]

I am planning on using a TLC2262 - don't know how close to the rails the LM386 will swing, but the TLC2262 can get to within a mV or so of the supplies, so it should have no effect on the distortion waveform. Will need static protection diodes on the output, as it's not got any of its own (thanks to...
by guiddruid
19 Oct 2009, 11:51
Forum: Boutique Stompboxes dissected...
Topic: WMD Geiger Counter - [gut shots]
Replies: 139
Views: 31193

Re: WMD Geiger Counter - [gut shots]

The code for the uC is trivial - you could replace the uC with an ADC, an EPROM lookup table, a couple of buffers (for the lookup table input / output bitdepth limiting), and a DAC. The uC is simply the more sensible approach; cheaper, more convenient for development... and apparently is sufficient ...