Resonant Electronic Design Acceleron Fuzz

mmolteratx · Post by **mmolteratx** » 30 May 2013, 23:23

weskuhnley wrote:
mmolteratx wrote:...I'm trying not to use my own stock of 5457s unless I absolutely have to.
Not going to pony up for 2500?

I bought 10k of them right before the prices got jacked up (bulk from Mouser at that point was ~5¢/piece, IIRC, total was several hundred dollars). Sold almost all of them at a profit on eBay though when they went up to 75¢/piece. Still have ~300 left, and I tend to use them for when someone asks me for an amp in a box type OD/distortion. Absolutely love them for that, much better than the J201, IMO. I just can't bring myself to spend so much on what used to be so cheap. Should've kept more.

Anyways, just realized that those caps are polyprop. Thought something was odd about the 1u in that size (especially with the 250V rating), and it's because it's a 100n polyprop. MKP2, I think.

toneman · Post by **toneman** » 31 May 2013, 00:48

MMBF5457 are available for 41cents each from mouser. surface mount only. same spec. but OH SO tiny!!

weskuhnley · Post by **weskuhnley** » 31 May 2013, 01:08

toneman wrote:MMBF5457 are available for 41cents each from mouser. surface mount only. same spec. but OH SO tiny!!

New layouts coming soon...but how does one sort SOT23 parts?

skywise · Post by **skywise** » 31 May 2013, 01:13

weskuhnley wrote:Also interesting you chose to put a (C) on your lifted schematic...just sayin.

Whoever draws any given schematic is the copyright holder of that particular drawing...according to the Copyright Act of 1976. Your drawing of the schematic is owned by you. If I redraw it as well, that drawing is mine. The individual artwork is owned by the creator at the moment of creation.

It would be "lifted" (or rather more precisely: copyright infringement) if Matt had taken your personal drawing of the schematic without your permission and posted it.

But please, do carry on...

skywise · Post by **skywise** » 31 May 2013, 01:26

Here are some shots for posterity. Oh, and these photographs were taken by me, composited by me, etc. They are not stolen.

mmolteratx · Post by **mmolteratx** » 31 May 2013, 01:33

weskuhnley wrote:
toneman wrote:MMBF5457 are available for 41cents each from mouser. surface mount only. same spec. but OH SO tiny!!
New layouts coming soon...but how does one sort SOT23 parts?

You can grab an SOT23 socket and build a little test board. I've thought about doing this for a while, but have never gotten around to it. I just don't use them enough to other at the moment.

toneman · Post by **toneman** » 31 May 2013, 02:23

New layouts coming soon...but how does one sort SOT23 parts?

what molteratx said also.
though, I don't recall ever seeing a "SOT socket"

U need to make a "SOT_matcher" fixture.
I think RG made a JFET matcher a while ago.....(?)
etch small little SOT pads next to the EBC of the thru-hole part.
put a heaping solder-coat on those pads.
Use tweezers, not fingers. (Fingers add heat.)
place the SOT on the pads and hold down with a wooden stick.
then press the test button and read the value.

mouser has price break at 25.

As with all JFETS, you might need to adjust the bias to find the "sweet spot".
I use a resistor box to find the correct value, then find a resistor within 1%.

afn
T

mmolteratx · Post by **mmolteratx** » 31 May 2013, 02:29

They're pricey. Here's an example. Cheaper on eBa though.

http://www.newark.com/wells-cti/499-p44 ... dp/25M4070

weskuhnley · Post by **weskuhnley** » 31 May 2013, 02:38

mmolteratx wrote:
weskuhnley wrote:
toneman wrote:MMBF5457 are available for 41cents each from mouser. surface mount only. same spec. but OH SO tiny!!
New layouts coming soon...but how does one sort SOT23 parts?
You can grab an SOT23 socket and build a little test board. I've thought about doing this for a while, but have never gotten around to it. I just don't use them enough to other at the moment.

Twas a rhetorical question.

And to the (C) commentary...thanks for the info. I was merely bemused that a forum dedicated to deconstructing other people's work needed to take such precautions. I suppose not all builders find your activities as benign as I do. Viva DIY or somesuch!

skywise · Post by **skywise** » 31 May 2013, 12:39

weskuhnley wrote:I suppose not all builders find your activities as benign as I do.

Most certainly not.

This one daft git even claimed that any photograph taken of his pedals (inside or out) by anyone was automatically his copyright because it was his product. Even if the pedal was owned by someone else and photographed by someone else. You'd think a dude smart enough to convince people to pay $800 for a delay pedal would be smart enough to have a basic understanding of copyright in the country he resides and does primary business. You would think that, but you would be wrong.

Good on you for not getting all bent out of shape.

On the other side of that coin are builders who at least on some level are okay with and even help out what goes on here. Wampler, Jack Deville, Skreddy, Lance Keltner (j/k), Brian from Subdecay, to name a few. Cool dudes, all around.

sinner · Post by **sinner** » 31 May 2013, 12:46

Bjorn also was coolio with us - at least up to the point

MoonWatcher · Post by **MoonWatcher** » 31 May 2013, 14:45

toneman wrote:
New layouts coming soon...but how does one sort SOT23 parts?
what molteratx said also.
though, I don't recall ever seeing a "SOT socket"

U need to make a "SOT_matcher" fixture.
I think RG made a JFET matcher a while ago.....(?)
etch small little SOT pads next to the EBC of the thru-hole part.
put a heaping solder-coat on those pads.
Use tweezers, not fingers. (Fingers add heat.)
place the SOT on the pads and hold down with a wooden stick.
then press the test button and read the value.

mouser has price break at 25.

As with all JFETS, you might need to adjust the bias to find the "sweet spot".
I use a resistor box to find the correct value, then find a resistor within 1%.

afn
T

I work under the presumption that I will use all SMT parts for something, eventually. With that in mind, if such SMT parts will be used for quasi-transitional through hole projects (I've got a working layout that I like, and will only bother with a SMT layout some time in the future, if at all), I solder them to little scratch built adapters. In the case of a transistor, it's pretty simple, and easy to have 3 G/D/S or E/B/C through hole leads extending from such an adapter. A 16 pin chip may require a different strategy, but the transistors are a no brainer.

It's also a great way to use up all those little left over pieces of copper clad or perf/vero.

You basically end up with a through hole part, so you can plug it into your existing projects, or your existing test equipment.

Maybe not very elegant, but it works...

weskuhnley · Post by **weskuhnley** » 31 May 2013, 15:17

skywise wrote:
weskuhnley wrote:I suppose not all builders find your activities as benign as I do.
Most certainly not.

This one daft git even claimed that any photograph taken of his pedals (inside or out) by anyone was automatically his copyright because it was his product. Even if the pedal was owned by someone else and photographed by someone else. You'd think a dude smart enough to convince people to pay $800 for a delay pedal would be smart enough to have a basic understanding of copyright in the country he resides and does primary business. You would think that, but you would be wrong.

Good on you for not getting all bent out of shape.

On the other side of that coin are builders who at least on some level are okay with and even help out what goes on here. Wampler, Jack Deville, Skreddy, Lance Keltner (j/k), Brian from Subdecay, to name a few. Cool dudes, all around.

I've never seen the DIY scene as a threat. For the most part, members of these kinds of communities aren't going to buy new pedals anyway, it's no skin off my nose if they're spreading the word for me among their non-diy friends. So long as it stays hobbyists, I'm cool.

jalmonsalmon · Post by **jalmonsalmon** » 18 Aug 2014, 03:24

weskuhnley wrote:
toneman wrote:MMBF5457 are available for 41cents each from mouser. surface mount only. same spec. but OH SO tiny!!
New layouts coming soon...but how does one sort SOT23 parts?

Long way is to solder a ton on mini daughter boards... be a pita though

Methulsky · Post by **Methulsky** » 05 Nov 2016, 23:02

Hi everyone,
is the any special name for transistor configuration Q2&Q3 are forming?

floris · Post by **floris** » 06 Nov 2016, 10:21

Q3 seems to be a current sink for the signal amplifier Q2. I wonder why a relative complex current sink is used for such a simple gain stage. It's a fuzz, full of distortion, so why try to improve on the linearity (reducing distortion) of the Q2 gain stage, instead of just using an emitter resistor for Q2? Q1 is probably overloading Q2, which generates distortion. I wonder how much effect the current sink has on the distortion characteristic of the Q2 gain stage.