Park Fuzz Sound - 6.4uf caps?

[Bret608]

Hi everyone,

I am looking to do a Mk III build on Madbean's Pastyface board. I like the sound of the Park Fuzz Sound based on YouTube clips, and Brian does provide that version of the BOM. But it calls for 6.4uf electros and I can't find those at any of the usual suppliers. Does anyone know where those can be found?

Thanks!

[armdnrdy]

About the closest you're going to get with an easily obtainable part is a 6.8µf tant.

Mouser doesn't even list a 6.4µf.

http://www.taydaelectronics.com/capacitors/tantalum-capacitors/6-8uf-25v-radial-tantalum-capacitor.html

[DDD]

4.7 or 6.8 uF is a good replacement value. Maybe, 10 uF is to be good, too.

[Mark Hammer]

Given the tolerance of those caps in bygone eras, I suspect the only thing that was 6.4uf was the printing on the cap exterior.  The extra nominal 0.4uf will not make any appreciable difference in the bandwidth.

[Bret608]

Thanks everyone--I may just socket those positions and try 4.7uf or 10uf. I notice the Sola Sound specs use 10uf. A couple of resistor values are different but nothing huge.

[GGBB]

According to the EIA decade standard, the closest value would be 6.42uF which is from the E192 series (0.1%, 0.25%, 0.5% tolerance).  Actual 6.40uF would be a custom value or perhaps NOS item - not cheap.  E192 caps are usually very small values, so realistically you will never find 6.42uF made, nor will you likely find the next closest value 6.34uF 1% (E96).  You might find the next closest 6.2uF 2% or 5% (E24), but if you do they won't be cheap.  As others have said, 6.8uF should be fine.  If you're picky, you can get a little closer with two 3.3uF in parallel.  However, due to the tolerances on cheap electros (5% or 10%), one 6.8uF could be closer than two 3.3uF.  If you test a bunch of 10% 6.8uF, you might find one that is about 6.4uF.

[LucifersTrip]

it's looks like u could fit 2 x 3.3's in parallel on that board (c3). there's a little extra space on both sides

[Gus]

I would use a 10uf.  Often older electrolytic's could measure higher then the marked value so the original might have measured closer to 10uf than 6.something when new
Do you have a link to the circuit?

[pappasmurfsharem]

http://www.taydaelectronics.com/capacitors/tantalum-capacitors/6-8uf-25v-radial-tantalum-capacitor.html

[armdnrdy]

http://www.taydaelectronics.com/capacitors/tantalum-capacitors/6-8uf-25v-radial-tantalum-capacitor.html

See reply #1 this thread. 

[pappasmurfsharem]

http://www.taydaelectronics.com/capacitors/tantalum-capacitors/6-8uf-25v-radial-tantalum-capacitor.html

See reply #1 this thread. 

Hah! It would appear I glazed over it.

[PRR]

> According to the EIA decade standard

Yes, but this is 1960s stuff.

The rationalized values came later.

Electrolytic caps were originally 8uFd. Then 16uFd. Then they introduced a whopping 32uFd. Even 64uFd. All at 450V.

E-cap values tended to be multiples of 8 for the next 30-40 years. "6.4" is one-tenth of a 64uFd (literally: they'd use 10 yards of foil for 64uFd, 1 yard for 6.4uFd.)

Even though all along the technology got smaller and low-Volt units became common.

I am *sure* the originals were +/-20% at best. So a "6.4" could be 5.3 or 7.7. If you need to have the exact sound that player X got on album Y, his pedal could be anywhere in that range (and probably a bit further out due to low-bid buying, factory screw-up, and aging).

With modern good-spec e-caps I'd try either two 3.3uFd, or a handful of 1uFd connected for 4 5 6 7 8 uFd total, selected by ear.

[Electric Warrior]

Hi everyone,

I am looking to do a Mk III build on Madbean's Pastyface board. I like the sound of the Park Fuzz Sound based on YouTube clips, and Brian does provide that version of the BOM. But it calls for 6.4uf electros and I can't find those at any of the usual suppliers. Does anyone know where those can be found?

Thanks!

MKIII/IV/Parks/... used 5µF, 6.4µF and 10µF interchangeably in that spot.
If you're going after the sound of a particular unit, it's more important to find out which bias setup it uses.

With modern good-spec e-caps I'd try either two 3.3uFd, or a handful of 1uFd connected for 4 5 6 7 8 uFd total, selected by ear.

Modern caps are usually rated 20% as well. At least the stuff I've been using (Vishay/BC and Panasonic).

[Bret608]

Thanks everyone--this has been educational, for sure. Based on what Gus and Electric Warrior suggest/mention, I will most likely just try a 10uf first for that position. Other than that, what are peoples' thoughts on the 100k/680k vs. the 47k/220k bias setup? Does one lead to a more aggressive tone than the other? Those positions seem to be the only difference between the Park vs. Sola Sound specs. They both sound so good on the clips I've heard, it's hard to choose! 

[Electric Warrior]

Those are not "Park" or "Sola Sound" specs. Any MKIII/IV type came with whatever bias string Sola Sound was using at the time. The earliest units had 150k/680k, but they changed it to 100k/680k early on. The 47k/220k was used from 1972 onwards. I've seen it in several Parks as well.

I haven't tried the 100k/680k string yet. 150k/680k can get quite a bit nastier than 47k/220k.

[Bret608]

Thank you, that helps a lot. I find the history of all the Sola Sound-produced fuzzes pretty interesting. All those less-than-definitive sets of specs add up to a lot of fun tweaking and experimenting...