Time for a small break again.
So I think it is time to release beast that I traced with lots of help by evilarsen and built it up a few months ago. It is not a Matamp amp emulator per se, more of a fuzzy overdrive that simulates the sound of a cranked Matamp. It also includes a power amp emulator section and a gyrator boost section at the end of the circuit. Also you can use MAX10044 or ICL7660S for the charge pump if you plan to run it on 9v only which sounds best IMHO.
Beyond excited to build this. Do you think an LT1054 would work for the charge pump? I have one of those lying around.
ReplyDeleteYes, you can use a LT1054. But it requires some small mods. First. Add a cut between pin 1 and 8 of the charge pump at the G5 pad. Two: don't solder in the 47uF cap left to the charge pump. It should be soldered across pad T8 (posistive leg) and S8 (negative leg).
DeleteI hope you'll get it working. I love this thing!
what changes would be nececassary if 7660s or max chip?
DeleteThey are drop in replacement so no tweak is necessary.
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ReplyDeleteGreat stuff as always! Is the schematic available? Thinking about drawing a PCB design for me to etch here. Thank you!
ReplyDeleteYes, I have the schematic but I'm a bit hesistant to upload it here since Magic pedals/Dunwich is basically a one man operation and this design is pretty unique both in topology and soundwise. But if I can get in touch with you I can send you the schematic so you can etch your own PCB. :-)
DeleteThank you for your reply. How can I get in touch with you? I couldn't find an email address.
Deletei think 47u above Q4 is reversed and 10K need to move from L20 to K20.
ReplyDeletemaybe im wrong, but that from try tracing from your vero. I just want it in perf.
I understand it can be confusing if you don't have the schematic on hand and the fact that the pre amp section Q1 through Q3) runs on normal power supply while the power amp emulator section (Q4 and a quarter of TL074) runs on bipolar power supply.
DeleteThe 47uF cap is in the correct orientation since it is a power filter cap for the negative power supply (positive leg to ground and negative to -9v). As for the 10k resistor it is connected across the Source of Q4 and once again negative power supply. So the reistor placement is correct.
wait, otw email my trace scan, please corrected then.
DeleteHi, I have a Petty John Gold MKI if you want pictures.
ReplyDeleteHow come there is No one doing Vero layouts for Abominable Electronic pedals like hail satan, sunnbather and such?
ReplyDeleteOr No one really into them? They are not that innovativa but stiłl cool pedals.
Abominable Electronics went under my radar...
DeleteI'll see if we can do anything, but I can't promise anything.
I can't seem to hear any difference with in the boost. Treble seems to have little effect also. Anyone else notice this?
ReplyDeleteHey Matt! Nice to see you around here!
DeleteThe Boost control is very noticiable in my build and the in the real units. Turned CW is bordering to almost oscillating wah territory.
Treble control is more subtle but it does the job. So unfourtenly I think you have a mistake somewhere.:-/
For the Boost control, check the voltages for the TL074 and check components placement and cuts close to pin 1,2,3,8,9,10,12,13 and 14.
yea I got a problem somewhere. The only voltages I have on the 074 is
ReplyDeletePin 4 +8.82
Pin 11 -7.57
Pin 14 1.35
Thanks for giving me direction @fuzzhead. When I first built this I thought it may just be the way it sounded with my amp. NOPE!! Holy Crap this thing is a beast. I started poking and prodding after checking where you said. DUHHH Matt, you gotta solder pin 14. LOL. After I took care of that I fired it up and tweaked the trim pot again. I LOVE this thing. Thanks for the info and making me think. Yes boost is very noticeable.
ReplyDeleteI'm building a stripped down version with a toggle switch for the Depth control instead of the rotary switch and I wonder witch cap values would you vhoose if you were to pick only three of those. I had a first of go with something like 2.2n, 22n and 100nf. What would you go for? TIA
ReplyDeleteSounds like good values! But I would use 1nF instead of 2,2nF...
DeleteSo I built this and it sounds amazing!! Is there anyway you could email me the schematic at dolander92@gmail.com? I'm interested in seeing what makes this circuit tick and making some mods for my own personal use. Thank You!
ReplyDeleteAwesome work as always, friend! Would it be possible for you to send me the schematic? Like the gentleman above, I would like to develop my own etchable layout
ReplyDeleteHave built this and it sounds really great. The depth control is very subtle though, for anyone else who's built this, how was the depth control on yours?
ReplyDeleteI think you need to double check the area sorrounding the TL074 for solder bridges, cuts, component placement and values. The Mid is control is anything but subtle...
DeleteThanks, will go over everything and check.
DeleteHave taken the board out the enclosure and checked over everything. All looking as it should, checked for continuity between tracks, all good there as well. Also checked the capacitance across the 1nf cap and turned the rotary to each position and the capacitance increased with each turn. Not sure what was up before but it's working now. It's a brilliant pedal! Thank you for the great layout!
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