Wampler - Velvet Fuzz  [traced]

General documentation, gut shot, schematic links, ongoing circuit tracing, deep thoughts ... all about boutique stompboxes.
User avatar
mganzer
Information
Posts: 49
Joined: 15 Jul 2011, 12:31
Has thanked: 32 times
Been thanked: 26 times

Post by mganzer »

just one dpdt doens't do the job on switching boosts?

User avatar
Lucifer
Cap Cooler
Information
Posts: 671
Joined: 06 Apr 2011, 12:59
my favorite amplifier: Vyse BBQ Blue
Location: Dorset, UK
Has thanked: 89 times
Been thanked: 72 times

Post by Lucifer »

I'm sure - with a bit of creative thinking - we could do away with the 386 side altogether, and just have the one boost circuit with two different gain/tone settings.

I'm gonna build mine that way and just play around with a few values till I get the sounds I want.

There'll be fewer components, a smaller/simpler board, and the switching should hopefully become simpler too.

For someone like me, with no brain, it's a no-brainer.
”Sex is great - but you can’t beat the real thing !” - The Wanker’s Handbook

User avatar
Nocentelli
Tube Twister
Information
Posts: 2222
Joined: 09 Apr 2009, 07:06
Location: Leeds, UK
Has thanked: 1152 times
Been thanked: 954 times

Post by Nocentelli »

mganzer wrote:just one dpdt doens't do the job on switching boosts?
It may well work. I haven't bothered connecting the third pole of my 3PDT fuzz switch (the pole that grounds the unused input) and I haven't noticed any problems. However, even with the 386 input grounded, at maximum fuzz level setting, the Fat mode fuzz squeals a bit with high frequency self-oscillation. It did this when it was on the breadboard, and does it still now it's boxed up. Whether this because of the lack of optoFETs, or is wiring/layout-related or something else, I can't say.
Lucifer wrote:I'm sure - with a bit of creative thinking - we could do away with the 386 side altogether, and just have the one boost circuit with two different gain/tone settings.
Well worth experimenting: I had the same idea, and tried three different solutions - I first used a standard fuzzface gain control on the 2N5089, then I tried a switch between a 10uF and 0.1uF emitter cap, and then I tried a 1k pot with lug 2 to emitter, lug 1 via 0.1uF to ground and lug 3 via 10uF to ground - All in an effort to shift the low-end boost to a higher range to emulate the "tight" setting. However, I think there must be some other quality to the boost provided by the 386 chip that yields the "tight" sound, since altering the emitter cap value changes the fuzz amount, but not so much the "quality" of the fuzz. Maybe switchable output caps from the BJT might work better than the approaches I tried.
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...

User avatar
mganzer
Information
Posts: 49
Joined: 15 Jul 2011, 12:31
Has thanked: 32 times
Been thanked: 26 times

Post by mganzer »

Well. Not a great layout. For shure not my best but...
Absolutely NOT VERIFIED!
Attachments
WVFboard.pdf
(182.7 KiB) Downloaded 453 times
WVFschem.pdf
(255.18 KiB) Downloaded 542 times

User avatar
crw414tele
Information
Posts: 44
Joined: 31 Jul 2013, 00:47
Has thanked: 16 times
Been thanked: 15 times

Post by crw414tele »

I can now say that my boost only vero is verified. Now for some observations. Take it as you will I don't have any other fuzz to compare to and I haven't explored it's setting fully
1 . Small amount of noise probably caused by not being boxed so shouldn't be an issue [ ymmv ]
2 . I used Mpsa18 instead of 2089 and that side has some fuzz on it's own and a huge bottom end ,noticeably bigger than the 386 side when using boost on it's own. The difference is less when stacking with another circuit.the 386 side sounds more like an overdrive on it's own to me.
3 . Seems to be a small volume drop when pushed into another pedal . Happens with both sides of the circuit , it's not huge and is easily fixed by increasing other pedals volume.
4. Using the levels seems to function similar to a guitar volume knob . As you turn down it becomes less wooly but I don't think the fuzz really changes much.
5 . It works well with other pedals , I stacked it into my black 65 and liked it a lot , the fuzz seemed to have a little more bite.I also used my boiling point on the LED side and that too worked well.
6. The gain knob on whichever pedal you stack into has a big effect on how overpowering the fuzz can be. I managed to get the plexi drive to sound like it had a slight dirty boost more than a fuzz with a few tweaks.
7. If you were to use the boost as a pedal on it's own it would benefit I think from some sort of eq.
8 . I did connect the switch so the opposite input is grounded and I didn't have any noticeable issues , but I am only playing at loud bedroom volume.
I've got plenty of experimenting to do before I decide how it will be boxed yet. At this stage I may box it with the plexi drive but have the boost so I can use it with or without the plexi circuit, 2 pedals in 1 and a sort of second channel for other pedals.
Thanks for the help.. :D
Almost forgot , it adds a heap of sustain , it like lead playing
Attachments
velvet fu## boost sectionv1.1.png

User avatar
crw414tele
Information
Posts: 44
Joined: 31 Jul 2013, 00:47
Has thanked: 16 times
Been thanked: 15 times

Post by crw414tele »

Just been thinking :hmmm: If the boost section of the velvet fuzz I've just built has a small volume drop when stacked with another circuit can it really be called a boost? What would be better , initial gain stage ? fuzzy stage ? I wouldn't say it's a fuzz on it's own , not enough fuzz but stacked It certainly increases gain , but not volume.

User avatar
crw414tele
Information
Posts: 44
Joined: 31 Jul 2013, 00:47
Has thanked: 16 times
Been thanked: 15 times

Post by crw414tele »

I think I should clarify that in testing I didn't have a bypass switch wired so I'm unsure what volume the boost/fuzz section has on it's own compared to bypass. I had it plugged in at the start of my pedal board and had it stacking into my plexi drive. So it could be the volume of the plexi causing the drop not the fuzz circuit. I'll do some more testing after my weekend of nightshifts

User avatar
Philster
Information
Posts: 24
Joined: 29 May 2012, 13:23
Has thanked: 7 times
Been thanked: 1 time

Post by Philster »

I built up the boost section but I'm getting just splatty farts on the tight side and zero on the fat side - I have triple checked component placing and all is good. Also the soldering is clean, so I'm wondering if I've missed something? I'm using a 2n5088 instead of a 5089 but the pinout is the same, yes? And I've got the 4n7 instead of the 4.7pf.
And if I want to leave off the pots so its full boost do I just connect the wires going to lugs 2 and 3?
Cheers
Philly

User avatar
Nocentelli
Tube Twister
Information
Posts: 2222
Joined: 09 Apr 2009, 07:06
Location: Leeds, UK
Has thanked: 1152 times
Been thanked: 954 times

Post by Nocentelli »

Philster wrote:I'm wondering if I've missed something?
Quite possible. I would have thought a 5088 would work in place of the 5089.
Philster wrote:...if I want to leave off the pots so its full boost do I just connect the wires going to lugs 2 and 3?
I wouldn't. The trimmed down layout above has added pots to control the output level of each "fuzz boost" separately. This was done by removing the two pairs of resistors that are part of the original velvet fuzz: Each pair acts as a voltage divider on the output of each section, or "preset output level". The tight side originally had a 3k3 in series with 2k2 to ground, giving an output of 2.2/5.5k = 40% of the unattenuated output. The fat side has an 82k series and 20k to ground giving around 20% of the maximum output. If you leave off the pots and do not put the original voltage dividers back in, the outputs will be massive, and also unbalanced, and I imagine it will not sound much like the velvet fuzz.
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...

User avatar
crw414tele
Information
Posts: 44
Joined: 31 Jul 2013, 00:47
Has thanked: 16 times
Been thanked: 15 times

Post by crw414tele »

If you leave off the pots and do not put the original voltage dividers back in, the outputs will be massive, and also unbalanced, and I imagine it will not sound much like the velvet fuzz.
What Nocentelli has said about the pots is true with both levels wide open the output is huge , I've only tested it for a short while but both side definately sound better with the pots rolled back

User avatar
jallenshaw
Breadboard Brother
Information
Posts: 57
Joined: 15 Jan 2012, 11:27
Has thanked: 7 times
Been thanked: 6 times

Post by jallenshaw »

crw414tele wrote:
If you leave off the pots and do not put the original voltage dividers back in, the outputs will be massive, and also unbalanced, and I imagine it will not sound much like the velvet fuzz.
What Nocentelli has said about the pots is true with both levels wide open the output is huge , I've only tested it for a short while but both side definately sound better with the pots rolled back
I plan on setting up my drive pots to be "stock" at 12 noon....IOW, I will measure the pots in circuit and have them set to the stock voltage divider values, then install the knobs to be straight up/12:00 at that value....that will make it easy to find the stock setting in case nothing else sounds as good.... :hmmm:

JAS

User avatar
andregarcia57
Cap Cooler
Information
Posts: 572
Joined: 16 Nov 2008, 15:42
Has thanked: 72 times
Been thanked: 108 times

Post by andregarcia57 »

crw414tele wrote:I can now say that my boost only vero is verified. Now for some observations. Take it as you will I don't have any other fuzz to compare to and I haven't explored it's setting fully
1 . Small amount of noise probably caused by not being boxed so shouldn't be an issue [ ymmv ]
2 . I used Mpsa18 instead of 2089 and that side has some fuzz on it's own and a huge bottom end ,noticeably bigger than the 386 side when using boost on it's own. The difference is less when stacking with another circuit.the 386 side sounds more like an overdrive on it's own to me.
3 . Seems to be a small volume drop when pushed into another pedal . Happens with both sides of the circuit , it's not huge and is easily fixed by increasing other pedals volume.
4. Using the levels seems to function similar to a guitar volume knob . As you turn down it becomes less wooly but I don't think the fuzz really changes much.
5 . It works well with other pedals , I stacked it into my black 65 and liked it a lot , the fuzz seemed to have a little more bite.I also used my boiling point on the LED side and that too worked well.
6. The gain knob on whichever pedal you stack into has a big effect on how overpowering the fuzz can be. I managed to get the plexi drive to sound like it had a slight dirty boost more than a fuzz with a few tweaks.
7. If you were to use the boost as a pedal on it's own it would benefit I think from some sort of eq.
8 . I did connect the switch so the opposite input is grounded and I didn't have any noticeable issues , but I am only playing at loud bedroom volume.
I've got plenty of experimenting to do before I decide how it will be boxed yet. At this stage I may box it with the plexi drive but have the boost so I can use it with or without the plexi circuit, 2 pedals in 1 and a sort of second channel for other pedals.
Thanks for the help.. :D
Almost forgot , it adds a heap of sustain , it like lead playing

where do I find good price for Pad Per Hole?

this is good?

https://www.ebay.com/itm/10-Pcs-Prototy ... 485afec449

User avatar
crw414tele
Information
Posts: 44
Joined: 31 Jul 2013, 00:47
Has thanked: 16 times
Been thanked: 15 times

Post by crw414tele »

I don't use that type so I'm not sure ,I get my vero stripboard from Tayda http://www.taydaelectronics.com/hardwar ... opper.html

User avatar
deltafred
Opamp Operator
Information
Posts: 1654
Joined: 06 Apr 2010, 16:16
Location: England
Has thanked: 813 times
Been thanked: 306 times

Post by deltafred »

andregarcia57 wrote: where do I find good price for Pad Per Hole?

this is good?

https://www.ebay.com/itm/10-Pcs-Prototy ... 485afec449
That is what I use, never had any problems with it.

I solder the components in, clip the leads off then make the inter-connects with thin wire (one of the many conductors from flexible connecting wire) rather than try to use the component leads. Makes assembly and any future component removal much easier.
Politics is the art of so plucking the goose as to obtain the most feathers with the least squawking. - R.G. 2011
Jeez, she's an ugly bastard, she makes my socks hurt. I hope it's no ones missus here. - Ice-9 2012

User avatar
jallenshaw
Breadboard Brother
Information
Posts: 57
Joined: 15 Jan 2012, 11:27
Has thanked: 7 times
Been thanked: 6 times

Post by jallenshaw »

crw414tele wrote:I don't use that type so I'm not sure ,I get my vero stripboard from Tayda http://www.taydaelectronics.com/hardwar ... opper.html
Same here.....the layouts on this thread are done with vero stripboard, not "pad per hole"...wrong stuff. Using what you ref'd will take lots of extra work and redesign, IMO

JAS

User avatar
jallenshaw
Breadboard Brother
Information
Posts: 57
Joined: 15 Jan 2012, 11:27
Has thanked: 7 times
Been thanked: 6 times

Post by jallenshaw »

Parts arrived today, so build is started (enclosure prep & painting first)

Found a hidden cut that was not needed, so I deleted it and updated the layout.
Hopefully will be verified later this week.

JAS
Attachments
Velvet Fuss Vero1.3.gif

User avatar
jallenshaw
Breadboard Brother
Information
Posts: 57
Joined: 15 Jan 2012, 11:27
Has thanked: 7 times
Been thanked: 6 times

Post by jallenshaw »

Progress on the build
The Fuss top.JPG
The Fuss guts.JPG
JAS

User avatar
Ripdivot
Resistor Ronker
Information
Posts: 316
Joined: 19 Jan 2008, 19:15
Location: Canada
Has thanked: 8 times
Been thanked: 78 times

Post by Ripdivot »

Well I decided to breadboard this bad boy today. I don't have an LM386 in stock so I decided to play with the 2n5089 circuit to try and make it do the "big" and "tight" settings. Obviously I don't have the original tight circuit to compare to but I still managed acceptable results.

First off I found that if the circuit is in "big" mode (stock 2n5089 circuit) and you back the fuzz off a bit there isn't enough high end so I switched the 100pf bleed cap on the fuzz control to 220pf like on the original PlexiDrive gain control and it did the job.

For the "tight" setting I tried various i/p caps, o/p caps and emitter bypass caps. I found all that was necessary was to switch the 47uf emitter bypass cap to a .47uf and it tightened right up.

I'm looking forward to getting an LM386 to compare to. I might just leave it as is because it works well and is nice and simple the way I have it now. By the way I have never built the PlexiDrive prior to today and I think it sounds great by itself as well!

User avatar
Ripdivot
Resistor Ronker
Information
Posts: 316
Joined: 19 Jan 2008, 19:15
Location: Canada
Has thanked: 8 times
Been thanked: 78 times

Post by Ripdivot »

Ripdivot wrote:Well I decided to breadboard this bad boy today. I don't have an LM386 in stock so I decided to play with the 2n5089 circuit to try and make it do the "big" and "tight" settings. Obviously I don't have the original tight circuit to compare to but I still managed acceptable results.

First off I found that if the circuit is in "big" mode (stock 2n5089 circuit) and you back the fuzz off a bit there isn't enough high end so I switched the 100pf bleed cap on the fuzz control to 220pf like on the original PlexiDrive gain control and it did the job.

For the "tight" setting I tried various i/p caps, o/p caps and emitter bypass caps. I found all that was necessary was to switch the 47uf emitter bypass cap to a .47uf and it tightened right up.

I'm looking forward to getting an LM386 to compare to. I might just leave it as is because it works well and is nice and simple the way I have it now. By the way I have never built the PlexiDrive prior to today and I think it sounds great by itself as well!
Just occured to me that if you switch the 4n7 low pass filter cap on the output of the 2n5089 circuit to 33n at the same time you switch the other cap I decribed when switching to tight the low pass frequency will be the same as the LM386 circuit (482Hz).

User avatar
Ripdivot
Resistor Ronker
Information
Posts: 316
Joined: 19 Jan 2008, 19:15
Location: Canada
Has thanked: 8 times
Been thanked: 78 times

Post by Ripdivot »

Ripdivot wrote:
Ripdivot wrote:Well I decided to breadboard this bad boy today. I don't have an LM386 in stock so I decided to play with the 2n5089 circuit to try and make it do the "big" and "tight" settings. Obviously I don't have the original tight circuit to compare to but I still managed acceptable results.

First off I found that if the circuit is in "big" mode (stock 2n5089 circuit) and you back the fuzz off a bit there isn't enough high end so I switched the 100pf bleed cap on the fuzz control to 220pf like on the original PlexiDrive gain control and it did the job.

For the "tight" setting I tried various i/p caps, o/p caps and emitter bypass caps. I found all that was necessary was to switch the 47uf emitter bypass cap to a .47uf and it tightened right up.

I'm looking forward to getting an LM386 to compare to. I might just leave it as is because it works well and is nice and simple the way I have it now. By the way I have never built the PlexiDrive prior to today and I think it sounds great by itself as well!
Just occured to me that if you switch the 4n7 low pass filter cap on the output of the 2n5089 circuit to 33n at the same time you switch the other cap I decribed when switching to tight the low pass frequency will be the same as the LM386 circuit (482Hz).
OK I can confirm that switching both caps works great, sounds very much like the demos. I will still get an LM386 to compare but I'm really liking this! :thumbsup

Post Reply