LucifersTrip wrote:according to this, it's a power transistor....which is doubtfulsinner wrote:Nice, I see nothing (cheep shit screen I have here).
It's low gain transistor 10-40hfe... and NPN indeed
http://transistor-spravochnik.ru/descri ... n5580/5047
I built the ge version a while back with this schematic:
[ Image ]
It's a smooth, thin & very trebly (look at in/out caps!) fuzz with very good sustain. If you don't like the mushy-ness or darkness that you can get with some ge FF's, this is for you!
At the time, I had no idea what Q2C voltage was supposed to be, so I have an external pot. I believe Solidhex noted that it should be a bit higher than a Fuzz Face...but how high? Were there voltage measurements from an original in any threads here....
VOX (JEN) Tone Bender - circa 1966 - 197(?) [schematic]
- modman
- a d m i n
Information
- Posts: 4898
- Joined: 19 Jun 2007, 16:57
- Has thanked: 4411 times
- Been thanked: 2139 times
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal
- modman
- a d m i n
Information
- Posts: 4898
- Joined: 19 Jun 2007, 16:57
- Has thanked: 4411 times
- Been thanked: 2139 times
More 60s Vox SFT transistor Tone Bender guts
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal
- modman
- a d m i n
Information
- Posts: 4898
- Joined: 19 Jun 2007, 16:57
- Has thanked: 4411 times
- Been thanked: 2139 times
And here's a third one with still other caps
- Attachments
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal
- sinner
- Old Solderhand
Information
- Posts: 4709
- Joined: 06 Nov 2008, 17:16
- Location: ...no more
- Has thanked: 1031 times
- Been thanked: 909 times
Yep. They comes in all sorts of different flavours cap-wise
I got it covered and documented here
The ones ain't know shit about are the ones with silicon transistors. You know, the same board's layout but with silicons. Not the later ones with clipping diodes
I got it covered and documented here
The ones ain't know shit about are the ones with silicon transistors. You know, the same board's layout but with silicons. Not the later ones with clipping diodes
- ringworm
- Breadboard Brother
Regarding the silicon transistors, does someone know 'The Captain', to ask him? If the silicon gut-shot is indeed his... http://stompboxes.co.uk/forum/viewtopic ... =10#p12741
I definitely think one is 2N5550 but I can't read the other.
I definitely think one is 2N5550 but I can't read the other.
- sinner
- Old Solderhand
Information
- Posts: 4709
- Joined: 06 Nov 2008, 17:16
- Location: ...no more
- Has thanked: 1031 times
- Been thanked: 909 times
I have RE to many DAM and EFE pedals to be brave enough to ask him
- The Rotagilla
- Diode Debunker
Question for you guys. RG Keen’s schematic shows a 47k resistor in parallel with the 500k volume pot which (and correct me if I’m wrong) drops the value of the volume pot to 42.96k. Fuzz Central’s schematic omits the 47k resistor and shows a 50k volume pot. My question is this…is there any particular need for the 47k resistor?
Thanks!
Thanks!
The television will not be revolutionized.
- ljn
- Solder Soldier
Information
- Posts: 222
- Joined: 29 Nov 2014, 00:48
- my favorite amplifier: Sears 125 xl, Kasino U100-P
- Completed builds: Fuzzrite (Si and Ge versions) , univibe, companion fuzz, fuzz face(si version), FY-6 super fuzz, FZ-1S, Scrambler, Tone Bender MkI (nearly complete). I have modded my vox v847,Seymour Duncan tweak fuzz, my bass and my guitar ( slightly).
- Location: United States
- Has thanked: 7 times
- Been thanked: 7 times
Using the 47k resistor in parallel with the 500k volume pot cuts bass. If you use a 50k pot for volume, it isn't necessary.
- The Rotagilla
- Diode Debunker
That's what I thought, just wanted to check. Thanks!ljn wrote:Using the 47k resistor in parallel with the 500k volume pot cuts bass. If you use a 50k pot for volume, it isn't necessary.
The television will not be revolutionized.
- ljn
- Solder Soldier
Information
- Posts: 222
- Joined: 29 Nov 2014, 00:48
- my favorite amplifier: Sears 125 xl, Kasino U100-P
- Completed builds: Fuzzrite (Si and Ge versions) , univibe, companion fuzz, fuzz face(si version), FY-6 super fuzz, FZ-1S, Scrambler, Tone Bender MkI (nearly complete). I have modded my vox v847,Seymour Duncan tweak fuzz, my bass and my guitar ( slightly).
- Location: United States
- Has thanked: 7 times
- Been thanked: 7 times
Glad to help. Just remember that in these fuzz circuits, a smaller value on the volume control will always cut bass.
- The Rotagilla
- Diode Debunker
Also wondering about the resistor that goes from lug one to ground on the fuzz pot. I've seen schematics with a value of 820r and 8k2, has anyone verified that an 8k2 was ever used or is it a color band reading error?
The television will not be revolutionized.
- ljn
- Solder Soldier
Information
- Posts: 222
- Joined: 29 Nov 2014, 00:48
- my favorite amplifier: Sears 125 xl, Kasino U100-P
- Completed builds: Fuzzrite (Si and Ge versions) , univibe, companion fuzz, fuzz face(si version), FY-6 super fuzz, FZ-1S, Scrambler, Tone Bender MkI (nearly complete). I have modded my vox v847,Seymour Duncan tweak fuzz, my bass and my guitar ( slightly).
- Location: United States
- Has thanked: 7 times
- Been thanked: 7 times
Every schematic and gutshot I've seen of this circuit has a 820 between lug 1 of the attack control and ground. If you tried a 8k2, it would be so distorted that it would barely pass signal (if at all ).
- modman
- a d m i n
Information
- Posts: 4898
- Joined: 19 Jun 2007, 16:57
- Has thanked: 4411 times
- Been thanked: 2139 times
Here's what I could grab from a recent Reverb listing:
Transistor is as yet unseen RCA SK3004 (radiomuseum spec sheet):
Still a few for sale on Ebay (and he's gots da baax!) Here are the rest of the gutshots from the Reverb auction:
Transistor is as yet unseen RCA SK3004 (radiomuseum spec sheet):
Still a few for sale on Ebay (and he's gots da baax!) Here are the rest of the gutshots from the Reverb auction:
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal
- mozz
- Breadboard Brother
Probably was repaired sometime in the past. The RCA SK3004 is a cross to the factory transistor (and hundreds of others). I have some here, they are really crappy transistor leakage wise.
- modman
- a d m i n
Information
- Posts: 4898
- Joined: 19 Jun 2007, 16:57
- Has thanked: 4411 times
- Been thanked: 2139 times
Just posted those because they were such clear and beautiful gut shots... Red dot on the original transistor is paint, on the SK3004 it's marker. And period correct transistors are still available it seems. Now I'm even beginning to doubt the originality of that nice row of carbon comps... other gut shots of this pedals always show stranger assortments of resistors.
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal
- nightraven
- Breadboard Brother
The carbon comps look fine to me. This model was in production for several years, and so it's not unusual for the parts selection to change over time.modman wrote: ↑23 Jan 2022, 23:58Just posted those because they were such clear and beautiful gut shots... Red dot on the original transistor is paint, on the SK3004 it's marker. And period correct transistors are still available it seems. Now I'm even beginning to doubt the originality of that nice row of carbon comps... other gut shots of this pedals always show stranger assortments of resistors.
My grey Vox has the same set of resistors. Mine does, however, have a tropical fish input cap, instead of the Arco cap, but that's also normal because my Vox is ever so slightly younger than the one in your pics. (Don't mind the blue electrolytic -- I had to replace the dead Ducati with that one myself!) The shielded wiring is different between the two pedals as well, but both types have been seen used in other examples, so that's not suspicious either. It's just the RCA transistor that I haven't seen before. Would those have been available in Italy?
https://fuzzboxes.org | authoritative and clickbait-free resource for 1960s fuzz pedals