Astrotone - Fuzz  [schematic]

Discussion regarding early stompbox technology: 1960-1975 Please keep discussion focused and contribute what info you have...
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Seiche
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Post by Seiche »

mictester :mrgreen: :roll:

yeah I was thinking 2n2222 (the metal cans) or 2n2369.

what do you reckon could be the magical gold lead silicon transistor from the 60s mike p. is using?

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Post by okgb »

I made a ptp version with the sam ash schematic , sounds a little thin to me
[ back to back .047s to isolate the diodes ? ] I'll increase the input cap to the larger
analogeman value , any other tips ? tia regards Greg

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Post by Seiche »

okgb wrote:I made a ptp version with the sam ash schematic , sounds a little thin to me
[ back to back .047s to isolate the diodes ? ] I'll increase the input cap to the larger
analogeman value , any other tips ? tia regards Greg
it's actually the input and output caps that are both 0.47uF instead of 0.047uF.
analogman stated on his site, the original sounds thin and he made it fatter.

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Post by LucifersTrip »

Seiche wrote:Would this be the correct schem? can anyone confirm?

Image
most likely correct, since I believe this is confirmed:

Image

1.2M > 1M
470 > 1.8K

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Post by Seiche »

yeah i changed the schem on the beginning of this thread according to the changes that analogguru proposed, i assumed they are right, since he is usually right 8)

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Post by okgb »

changing the i/o caps helped allot , I'm assuming the other analogman changes were for the transistors ,
but how about the resister to the tone control ? seems to start cutting bass halfway mostly useless

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Post by Seiche »

okgb wrote:changing the i/o caps helped allot , I'm assuming the other analogman changes were for the transistors ,
but how about the resister to the tone control ? seems to start cutting bass halfway mostly useless
well, according to analogman the tone control makes it possible to get the sound of the original astrotone. as you described as thin, I assume that's what it's supposed to do :scratch:

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Post by okgb »

Sorry , I should have been more clear , the two cap changes made it usable for me . I didn't do any of the resister changes
the tone control may have become more subtle [ or maybe it's the same and I'm imagining it ] funny for a shunt type
control that it feels like it cuts bass , i'm not up on the theroy but can anyone say what affect changing the resister before
the tone control will have ?
I remember a few people changing the tone control , I'll look into that but, thanks for the help , the fuzz is allot of fun

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Post by Seiche »

hey okgb,

Saw your post on the Diaz Texas Ranger thread, about how you enjoyed this box.
have you had the chance to try to change the resistors yet? would be great to know if it gets more usable that way.

I haven't found an application yet for my rangemaster clone either :scratch:

cheers

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Post by okgb »

I twisted the leads of the parts together and soldered that , to replace caps i clipped out
the old ones [ ruining them ] but was hoping someone could tell how the resister changes may affect the sound
before i bothered [ if some are only to bias the transistors he used ? ]

I built the Viper version of the rangemaster Si , and it's not bad but the triboost , byoc kit that i bought already stuffed
sort of distorts on all 3 modes when you hit the strings a little hard , so i haven't been able to really experience or enjoy
the fabled Ge boost

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Post by mictester »

Seiche wrote:mictester :mrgreen: :roll:

yeah I was thinking 2n2222 (the metal cans) or 2n2369.

what do you reckon could be the magical gold lead silicon transistor from the 60s mike p. is using?
I've got a bag of "ME1120" transistors - gold-plated leads, little domed jobs with a µr logo on them. They're from the late 60s and have hfe figures between 50 and 100. They're superb in circuits like this!
"Why is it humming?" "Because it doesn't know the words!"

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Post by Seiche »

the 1M2 should not do much, maybe bias the transistor slightly different, or account for different HFe values (maybe higher Hfe transistors?).

the 470 on the tone control, however, should definitely change the sweep of the tone pot, maybe make it more useful. The bass cut happens because the tone control + R6 forms a high pass filter that changes by turning the tone control. A high pass filter lets high frequencies pass and attenuates bass frequencies.

cut-off frequency is:
Image

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Post by Seiche »

Did a quick little vero for the (alleged) Analogman version of the Astrotone Fuzz.

This version should fit in a 1590A enclosure and has no standup resistors.

Maybe a second (or third) set of eyes should look over it, though, before building it.

edit: updated version below

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Post by IvIark »

Seiche wrote:no standup resistors.
Important :mrgreen:
"If anyone is a 'genius' for putting jacks in such a pedal in the only spot where they could physically fit, then I assume I too am a genius for correctly inserting my legs into my pants this morning." - candletears7 - TGP

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Post by Seiche »

IvIark wrote:
Seiche wrote:no standup resistors.
Important :mrgreen:
you're a great teacher 8)

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Post by Nocentelli »

i'd rather have standy resistors than diagonals... :blackeye

(though you could move the tone1 connection down two rows, make another cut at column C/row D, and move that resistor so it's vertical).
modman wrote: Let's hope it's not a hit, because soldering up the same pedal everyday, is a sad life. It's that same ole devilish double bind again...

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Post by Seiche »

^thanks for the heads-up. I'd rather have diagonals than stand-ups (especially in an A), but I try to keep them straight usually. Plus that was an easy fix, no idea why I didn't see that.

now everybody's happy :thumbsup
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Post by Nocentelli »

Cool. I've just plugged this into the breadboard with 2N2222s and will try it out when i'm allowed. One question, how did you update/edit the attached picture? I've looked in the "manage attachments" section of the user CP, but can only delete previously posted schems: Or is this some kind of moderator magic?
modman wrote: Let's hope it's not a hit, because soldering up the same pedal everyday, is a sad life. It's that same ole devilish double bind again...

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Post by Seiche »

Nocentelli wrote:Or is this some kind of moderator magic?
yes. Mods can delete and edit everyone's posts. To be fair, though, I merely deleted it from the first post and reposted in a new post, that you should be able to do as well with the attachment feature you described.
I could've switched it out in the original post, though.

What do you mean by "when you're allowed"? Neighbours? Because I sure as hell ain't gonna stop you! :blackeye

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Post by Nocentelli »

Seiche wrote:I merely deleted it from the first post and reposted in a new post, that you should be able to do as well with the attachment feature you described.
I could've switched it out in the original post, though.
reading on a blackberry... thought you'd edited the original post :slap:
Seiche wrote:What do you mean by "when you're allowed"? Neighbours? Because I sure as hell ain't gonna stop you! :blackeye
kids and mrs nocentelli in bed. I tried it through headphones just now, though, and it sounds pretty cool! only very quiet strumming, since i play a semi acoustic and 'er indoors is convinced even that will wake the kids up...
modman wrote: Let's hope it's not a hit, because soldering up the same pedal everyday, is a sad life. It's that same ole devilish double bind again...

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