So here are two different Bosstones, one from Nashville one from California, and a Bossboost. Major differences all around. Big pictures so I thought I would do links.
http://i3.photobucket.com/albums/y57/c-martin/fuzzes/close%20shots/jordan-bosstones-both-compside.jpg
The Nashville one, transistors are M924 and 2N3565 (round one), GI301 diodes, and date code of mid 72 on the diodes, 3 stacked caps all .01, vertical cap 47n, resistor under wires looks like maybe a 47k?:
http://i3.photobucket.com/albums/y57/c-martin/fuzzes/close%20shots/jordan-bosstone-nash-wiring.jpg
http://i3.photobucket.com/albums/y57/c-martin/fuzzes/close%20shots/jordan-bosstone-nash-trace.jpg
http://i3.photobucket.com/albums/y57/c-martin/fuzzes/close%20shots/jordan-bosstone-nash-compside.jpg
California Bosstone, 2N3397 (yellow dot) and MMPS5513 (face down) verical cap is 220k, cap under other is .02 also, can not read diode values:
http://i3.photobucket.com/albums/y57/c-martin/fuzzes/close%20shots/jordan-bosstone-ca-wiring-circuit.jpg
http://i3.photobucket.com/albums/y57/c-martin/fuzzes/close%20shots/jordan-bosstone-ca-compside.jpg
http://i3.photobucket.com/albums/y57/c-martin/fuzzes/close%20shots/jordan-bosstone-ca-circuit.jpg
Bossboost shots, 2N2712 (yellow looking one) 2N3397 (other), knobs Bass (left) Treble (right):
http://i3.photobucket.com/albums/y57/c-martin/fuzzes/close%20shots/jordan-bossboost-wiring.jpg
http://i3.photobucket.com/albums/y57/c-martin/fuzzes/close%20shots/jordan-bossboost-compside-back.jpg
http://i3.photobucket.com/albums/y57/c-martin/fuzzes/close%20shots/jordan-bossboost-compside.jpg
http://i3.photobucket.com/albums/y57/c-martin/fuzzes/close%20shots/jordan-bossboost-circuit.jpg
Troublemaker! >:(
:icon_wink: So far that Californian is looking different from the DIY Bosstone we know and love. Have not started looking at the other yet.
Thanks for the killer photos!
And they sound completely different. The Nashville one is smoother, the California one sounds like it is ready to oscillate on almost every note. The boost is a nice clean boost. Now just have to find one more knob (got two off e-bay on a little passive mixer).
Hard to see, but this is what I get for the Alhambra:
http://users.rio.com/senorris/junk/bosstoneCA%3f.gif
About the knobs, seems I've seen something similar on one of those telephone amp things that strap right onto the earpiece. Unfortunately, most of them are beige...
Thanks again for the photos!
very informative
Any chance of schematics for comparison?
thanks
The Tennessee is like Arons schematic with some value changes:
http://users.rio.com/senorris/junk/bosstoneTN.gif
Dan,
Thanks for the work!
:)
Dan, great work! The volume pot is about 150k on the CA one. I had that pulled so I measured it.
Thanks man! Was just considering building one!
Interesting! I've also seen the Sho-Sound Nasville model with 3 - .05uF, 1 - 50pF, Q1 - MPS6513 and Q2 - 2N4249, unreadable diodes, resistors all the same as in Aron and R.G.s schematics. http://www.diystompboxes.com/pedals/bosstone.gif http://www.geofex.com/FX_images/bosstone.gif
Are those rectifier diodes? I can't find any data.
Thanks, for the great pics :icon_biggrin:
Richard
Chris, can you verify that that one cap in the Nashville is 47nf and not 47pf like in the other schematics?
Your description of the CA one has me raring to build one!
Quote from: Dan N on August 21, 2006, 12:28:51 AM
Chris, can you verify that that one cap in the Nashville is 47nf and not 47pf like in the other schematics?
Your description of the CA one has me raring to build one!
Okay, on closer inspection it says 47M. It is pretty chunky for a 47pF cap, but then again I have no clue on the voltage rating. Only other marking is the Z5F for the dielectric.
Hi
The bypass caps look like 47pF ceramic cap in both models. 47nF would be too much,
The rectifier diodes are said to be 1N4001, but both 1N4001 and 1N4148 sound good.
The Nashville one probably has similar gain in Q1 to the other, inspite of the higher collector resistance on Q1 (18K+47k instead of 18k +18k). More importantly, I *think* Q2 gives more active loading (3.6 times ((47k+18k)/47K) instead of 2 times ((18k+18k)/18k). Someone should check that - I get the maths mixed up sometimes.
If so, it makes the gain of this circuit much higher than the usual schematic. For example, if Q1 has hFE = 150, the circuit overall has gain of 150 x 3.6 =540, whereas it is only 150 x 2 =300 in the usual circuit (18k + 18k or 22k +22k resistors).
Which makes me think - why not use a 10k resistor and a 50k pot wired as a variable resistor in place of that fixed 47k resistor? I think that would give gains from about 250 to 600.
cheers
Thanks, Chris. I changed it on the schematic.
Interesting stuff, Brett! Thanks!
At some point this circuit went from being a hippy fuzz to a steel guitar tool. It appears that the Sho-Bud folks did some experimenting with values over the years.
Am I going to have to get a Sho-Bud version too? :icon_biggrin:
A buddy used the Nashville one on an album and loved it a lot more than his boutique version of it.
I think I am going to have to make a pedal that works with these so that you can have them on the floor. Maybe so you can put two in with two switches. That would rule.
More pics. Sho-Sound, Nashville, model 6248 on the box.
http://aronnelson.com/gallery/view_album.php?page=4&set_albumName=Richard-Boop-RLBJR65
Pretty! Does that one have anything to protect the circuit board from the battery? None of mine had anything good for these modern metalic batteries. I think there was foam in some a long time ago but that because goo much like the MXR foam.
Hi
This one seems to be the "standard" design with 2 x 18k resistors (brown-silver-orange-silver, one is partly hidden under the wires)
thanks for the photos
cheers
Quote from: Sir H C on August 21, 2006, 04:14:39 PM
Am I going to have to get a Sho-Bud version too? :icon_biggrin:
Ha ha, sorry, I was assuming Sho-Sound and Sho-Bud are the same folks. Don't know it for a fact. You probably have the Boss Tone corner of your collection covered.
RLBJR65, what a beauty! Thanks!
It is a beauty but its not mine :icon_sad: A friend sent the pics to me.
Sir H C, I saw lots of gut shots, these were the best. As far as I can see there was not any foam or anything else in there to keep the battery from bouncing around.
Anyone know where to get those input jacks?
Quote from: RLBJR65 on August 21, 2006, 09:08:10 PM
It is a beauty but its not mine :icon_sad: A friend sent the pics to me.
Sir H C, I saw lots of gut shots, these were the best. As far as I can see there was not any foam or anything else in there to keep the battery from bouncing around.
Anyone know where to get those input jacks?
The male jack? It looks like they took a standard 1/4" jack from switchcraft or the like and put a nut on it and called it an input. The output is just a stereo plastic jack, nothing special.
Two of the three had that ugly foam, seems another variable thing they did.
QuoteThe male jack? It looks like they took a standard 1/4" jack from switchcraft or the like and put a nut on it and called it an input.
I thought of that after I posted and went searching :icon_redface:
I don't think they have enough threads to go through an aluminum box. The mechanical drawings only show the tread size and not the length so I could be wrong.
Thanks
It is just a very thin piece of metal for the enclosure then immediately the nut. The other side has the gnarled look of most switchcraft male jacks.
I built the CA version and must confess was disappointed. Good crackly fuzz, but quick gated sustain. Real old school in a bad kind of way.
I switched the PNP to an NPN ( e to ground, b in and c out) and this little guy came roaring to life! Pretty damn good fuzz. Fuzzy with plenty of bass and nice sustain.
Here's a small pcb if anyone wants to try it. Kind of a tight squeeze for cap experimenting. Oh well.
http://users.rio.com/senorris/junk/jbtcapcb.gif
I also have some extra boards etched and drilled if anyone wants. Too small to just etch one...
Thanks for the new fuzz, Chris!
I used Q1- BC549C, Q2- 2N3904.
Funny that you bring up the Bosstone, I just finished mine last night!
8^)
I followed this schematic:
http://www.geofex.com/FX_images/bosstone.gif
I used the 1N914a diodes.
It's a pretty cool sounding fuzz, pretty nasty really but in a good way. I ended up putting in a switch to add a 0.1uF cap in parallel with the 0.022uF input cap, this really makes it go berzerk! I'll call it "FAT" mode I guess.
I'm not sure if my pedal actually sounds a whole lot like the originals though.
The M924, 2N3565, cross-select with an NPN (NTE 123) on the NTE site. The 2N3397 also comes up NPN but a different number. Can not find a cross listing for the MMPS5513 other than as a 2N5513 which is a FET.
So it seems that they did use two NPN transistors in this design, just that they were two different types.
Here are the trans specs. for the Bosstone I posted. Found these some time ago in an old thread that I can't seem to find now. Glad I save everything :icon_biggrin: Thanks to whoever posted them first!
(http://aronnelson.com/gallery/albums/album69/BossTrans.gif)
Sir HC A low Hfe 2N3904 works great for Q1. Q2 thats the strange one 200mW Hfe280.
It's funny that everyone seems to like the Nashville version with .02 caps but I've never actually seen one with them.
Is that maybe what Voodoo Lab had in theirs when they reissued them? Never seen the guts of one of those.
Richard
PS don't you love how almost every GP NPN you put into NTE's cross reference comes back to a NTE123 or 123A.
I have had my NTE and ECG guides since college (gads almost 20 years back!) and when I seen NTE-123 I just laugh.
Hey guys I was wondering if you could take a look at this PCB layout I did. I've looked over it several times and the layout looks sound but maybe some fresh eyes will find an error. http://aronnelson.com/gallery/album69/jordanbosstone?full=1
The reason I'm asking is the clone I built sounds very good but does not have as high a gain level as the original. I built it like the one I posted the pics of with .05 and 50pf ceramic caps all carbon comp resistors for Q1 2N3904 Hfe 140 - Q2 2N4249 Hfe 150. I used 100K pots for both the attack and level.
Hfe of Q2 looks a bit low according to the data maybe thats the problem.
The clone is currently with the owner of the original so I can't check the voltages until I get it back.
All pics and transistor data are posted in the same folder as the layout just scroll L or R.
Thanks
Richard
Are you sure about the outline for the PNP? Is the collector the opposite side as the NPN? Otherwise looks right.
Can always try an NPN in the second stage to get more gain.
Thanks for checking it out Sir HC.
Actually the 2N4249 is round so ignore the foot print drawn on the layout. I pretty sure the pinout is labled correct per schematic.
Added the schematic for Model 6248. http://aronnelson.com/gallery/album69/Bosstone_6248
Richard
These are some real nice Pics in this thread.
Thanks for the detailed info guys. :)
Thanks, I have pictures of other fuzz guts and can get photos of other ones that I have lying around too. Right now I have pictures of:
Sekova fuzz (Maestro FZ-1 clone)
Ampeg Scrambler (Pretty useless unlike you like the look of epoxy)
Arbiter Fuzz Face
Kay Fuzz
Maestro FZ-1 (can do a FZ-1A too)
Rosac Nu-Fuzz, Nu-Fuzz Nu-Wa, Distortion Blender
Crazytone (Fuzzface clone)
Sound City Fuzz Wah Face
UMI Fuzz
Hey gang, I decided to reply to this thread instead of starting a new one as it is packed with great info. I have been obsessed with the Jordan Boss Tone for some years and have dedicated many hours to their study. I have determined that there were a total of five different models. They all share the same box but the boards varied. I have met with one of the owners/designers of the Jordan line and he has helped answer some of my questions. I am working on a history of the Boss Tone and if anyone has info they care to share, I will include it.
Here are some photos of the timeline:
Version 1
(http://i94.photobucket.com/albums/l102/chrisguitars/Jordan%20Juniors%20and%20Boss%20Tone/DSCN1335.jpg)
Version 2
(http://i94.photobucket.com/albums/l102/chrisguitars/Jordan%20Juniors%20and%20Boss%20Tone/DSCN0539.jpg)
Version 3
(http://i94.photobucket.com/albums/l102/chrisguitars/Jordan%20Juniors%20and%20Boss%20Tone/DSCN1434.jpg)
Version 4
(http://i94.photobucket.com/albums/l102/chrisguitars/Jordan%20Juniors%20and%20Boss%20Tone/DSCN0541.jpg)
Version 5
(http://i94.photobucket.com/albums/l102/chrisguitars/Jordan%20Juniors%20and%20Boss%20Tone/DSCN1674.jpg)
I have made my versions of these as well as a version of Jordans tremolo called the Vico Vibe. I am also just finishing my version of the Orange Squeezer called the Orange Tone. It is the famous Squeezer with true bypass and LED, very cool sounding. Here are a few photos:
(http://i94.photobucket.com/albums/l102/chrisguitars/Jordan%20Juniors%20and%20Boss%20Tone/DSCN1667.jpg)
(http://i94.photobucket.com/albums/l102/chrisguitars/Jordan%20Juniors%20and%20Boss%20Tone/DSCN1669.jpg)
(http://i94.photobucket.com/albums/l102/chrisguitars/Jordan%20Juniors%20and%20Boss%20Tone/DSCN1654.jpg)
(http://i94.photobucket.com/albums/l102/chrisguitars/Jordan%20Juniors%20and%20Boss%20Tone/DSCN1653.jpg)
(http://i94.photobucket.com/albums/l102/chrisguitars/Jordan%20Juniors%20and%20Boss%20Tone/DSCN1676.jpg)
(http://i94.photobucket.com/albums/l102/chrisguitars/Jordan%20Juniors%20and%20Boss%20Tone/DSCN1664.jpg)
(http://i94.photobucket.com/albums/l102/chrisguitars/Jordan%20Juniors%20and%20Boss%20Tone/DSCN1454.jpg)
Hi Chris, it is pretty weird how the bosstone evolved. There are photos of what you call the first in this thread:
http://www.diystompboxes.com/smfforum/index.php?topic=57936.0
Do you have cap values for that first type? Is that a tantalum output cap? With these "timeline" circuits, how would you characterize their individual tones?
Very nice work on your clones!
Ha, if you ever wanted to share the schematic for the VicoVibe, this is the place to do it.
Hi Dan, I have tried to find the scheme but had no luck. I will post it when I find it. The first version does have a tantalum cap up top. That model is my next project and it should be easy as both transistors are the 2N3397. Once I lift the components I will measure them and let you know the values. That version that I have has a cool mod and it sounds unearthly good.
(http://i94.photobucket.com/albums/l102/chrisguitars/Jordan%20Juniors%20and%20Boss%20Tone/DSCN1329.jpg)
I was poking around on my hard disk and I came across a pic of a Jordan Boss Tone which looked different to the one that has been on Aron's site for the last 20yrs or so. Unfortunately I missed this thread when it was active.
If you look at the effect database pics the sticker changes from Jordan Electronics to SHO-Sound at some point. The circuit seems to go through three versions. The first two are similar but not the same. The last one is the one that's been on Arons site for some time. I don't know if there is any correlation between the company changes and the circuit changes. The model changes from 1000 to 6248 at some point as well.
Anyway, the one I had was this one, it's the very first version.
Circuit 1:
http://www.effectsdatabase.com/model/jordan/bosstone
Which has some details here,
http://tonemachines.blogspot.com/2011/10/jordan-boss-tone-1967.html
Here's a schematic of the circuit,
(https://i.postimg.cc/DyVhKxxz/Boss-Tone-Model-1000-V1-dwg-V1.png)
Just found this. It's the schematics for the second version and the last version (the one on Aron's site),
(https://farm6.static.flickr.com/5346/7051200737_63d96e373a_b.jpg)
So it's possible the value of C2 on the first version is 220pF.
Wow, cool thread. :D
Think I'll need to build a California Bosstone now
QuoteThink I'll need to build a California Bosstone now
FWIW, when I look at the circuit it seems to bias centrally for gains around 100, pretty low.
The datasheets 2N3397's have *ridiculously* wide spans for the gain. I've got no idea
what the typical gain would be in the actual units.
Anyway it's probably worth playing around with the biasing for best sound. That might turn out to sound better than the original ;D.
----------------------------------
Some useful info:
Based on the 2N2926 transistor, which is manufactured with the same process as the 2N3397, the transistors have colored dots indicating the gain.
2N2926 hFE
Unsorted: 35 to 470
Brown 50
Red 74
Orange 135
Yellow 225
Green 350
The pics for the Boss Tone V1 shows transistors with orange dots which corresponds to hFE=135.
That lines up reasonable well the value I calculated. The V2 pic shows the Q1 with a yellow dot which is hFE=225.
> Unsorted: 35 to 470
Low price. Specially in 1967.
The collector feedback greatly reduces bias variation. hFE=35-470 makes only 2.3:1 change of current.
Anyway, what's the worst can happen? It distorts. Isn't that what they were selling?
And as you note, some of these whole-hog bargain numbers were available dot-sorted.
QuoteAnyway, what's the worst can happen? It distorts. Isn't that what they were selling?
To me the biasing can make it or break it.
I guess there's two angles: one is to make a representative clone, the other is to make it as good as it can be. The last thing we want is to make clones that don't sound like the original or don't sound good! That's how a lot of germanium fuzz clones end up. At one point I made notes about vintage fuzzes from youtube videos and some of the worst and best were actually the same circuit!
Stuff found on my hard disk.
---------------------------------------------------------------------------------------------------
Boss Tone Info and Chrononology
Rob S, 2021/02/21
I've kept the common circuit numbering (1 to 5) from the web, but there's a bit more to it.
Also there's a difference between manufacturing build and the schematics alone.
All models are au-0606 until we get to the 6248 Sho-Sound
Alhambra (1967, 1968, maybe 1969)
Pasadena marked au-606 but has Nashville circuit
Features identifying versions:
- external labels
- pcb color and pcb number etched on solder-side
- transistor packages and location of transistor on boards.
- The California circuit puts the transistors on opposite corners of the PCB.
and the Nashville put the transistors in the same corner.
- parts marked ***
Revision History:
- added info on Pasadena unit
- added info on PCB markings
- resolved some of the transistor markings
---------------------------------------------------------------------------------------------------
California 1 schematic V1.0
C2 should be 220p
The transistors have dots which indicate the hFE's; see details below.
---------------------------------------------------------------------------------------------------
Circuit 1
Schematic: California 1
Label: Alhambra Calif, au-0606
PCB: IC-0193 B ; solder-side marking
PCB has a large square pad between the PCB number and mounting hole.
*** Diodes orientated across PCB;
Transistors:
2x2N3397 NPN, Package TO-98 skirt, orange dots
Orange dots => hFE=135, based on same process 2N2926
TO-98 is like a TO-92 with a round skirt at the bottom
Knobs: two different markings.
Circuit 2
Same design as Circuit 1 except different PCB
Schematic: California 1
Label: Alhambra Calif, au-0606
PCB: Likely IC-0193 C ; solder-side marking
*** Diode orientated along PCB
*** 100k orientated along PCB
(*** 33k & 470R loaded on PCB)
Transistors:
Both NPN, TO-92 but no dots. I expect 2xMPS6513
---------------------------------------------------------------------------------------------------
Circuit 3
Schematic: California 2
Label: Alhambra Calif, au-0606
PCB: IC-0193 C or D(?)
Ground hex post does not have a tinned area.
*** 100k (located near wires) mounted on an angle,
100k moved to mount Transistor in different holes,
red wire also moved.
Parts:
Links loaded in place of 33k & 470R.
Q1 feedback resistor 10MEG
Caps: 2x20n
Output cap: 20n
Feedback cap: 220p
Transistors:
Q1 2N3397 NPN, TO-98 skirt, yellow dot
Yellow dot => hFE=225, based on same process as 2N2926
Q2 Motorola MPS6513, NPN, TO-92, gold leads ; hFE = 90 to 180 @ 2mA, calc avg hFE = 135
Example: (Sir H C, 2006)
"California Bosstone, 2N3397 (yellow dot) and MMPS5513 (face down) vertical cap is 220k,
cap under other is .02 also, can not read diode values."
Note first M is the Motorola logo not the part number.
Circuit 4
Schematic: California 2 + cap mod
Same as circuit 3 except output cap is 470pF; Solar 470M Z5R.
The cap is thicker and is not stacked with the other caps in
the middle of the PCB.
---------------------------------------------------------------------------------------------------
Circuit 5 Nashville circuit with both transistors next to each other.
The upper transitor is the NPN and the one nearer the corner the PNP.
This have a number of sub variants.
Pasadena
Uses the "Nashville" circuit.
Has red white blue wires
Schematic: Nashville
Circuit: Nashville
Label:
Pasadena, South Pasadena California
PCB: Text "IC-0193 F"
Brown color on component-side
Dark green soldermask on solder-side
Parts: 100n input cap (Solar brand)
Others? (Solar brand)
2x 18k's
Transistors: Q1: Motorola SPSxxxx, NPN, TO-92, gold lead
Q2: ???, PNP, TO-92, gold lead
Diodes: 1N4001?, 1A rectifiers, Black, Motorola
Not fully Identified:
Similar to previous but different transistor packages.
Schematic: Nashville
Circuit: Nashville
Label: ?
PCB: Brown color on component-side
Parts: 10n input cap
Transistors Q1: NPN, TO-106 button
Q2: PNP, TO-92
Diodes: 1N4001
Not fully identified: (from a schematic)
Schematic: Nashville
Circuit: Nashville
Label: ?
PCB: ?
Parts: caps 2x18k, 3x10n
Transistors:
Q1: F70N1 1142812 (maybe E70N1), NPN; Probably F = fairchild
Q2: M852 95232, PNP ;implying M= motorola symbol 8 = 1968, 52 = wk52, part no. = 95232
A part source indicated: NTE159 = 2N3906 = 95232
Diode: 1N4001
Comments:
I have a suspicion the Fairchild part might be a TO-106 button head.
That would essentially be the same as next version with he 2N3565.
Nashville
Schematic: Nashville
Circuit: "Nashville" Circuit
Label SHO-Sound, Nashville
PCB: No PCB number.
PCB is light green semi-trasparent fibreglass
PCB tinned but with no soldermask.
Parts: (Sir HC unit)
3x10n
18k + 18k
Transistors:
Q1: 2N3565. NPN, TO-106 button package
Q2: Motorola 924 95232, PNP, TO-92
The M at the start of M924 is a Motorola Logo not the part number.
Likely to be date 1969 and part number 95232.
\E B C/ botton view, gold leads
Diode: GI (General Instrument)
look like 1A rectifiers.
Variants:
*** Caps seem to vary: 10n, 20n, 50n
Not fully identified:
Label: SHO-Sound, Nashville
PCB: ?
Parts:
RLBJR65 (Richard Boop)
Re: Jordan Bosstone and Bossboost pictures
« Reply #9 on: August 20, 2006, 11:05:42 PM »
"Interesting! I've also seen the Sho-Sound Nashville model with
3 - .05uF, 1 - 50pF, Q1 - MPS6513 and Q2 - 2N4249, unreadable diodes, ..."
Q2: 2N4249 hFE = 100 to 300, PNP, Silicon
Comment on this:
MPS6513 NPN is a TO-92 package, and the PNP 2N4249 is a TO-106 button.
This swaps the position of the TO-92 and TO-106 compared to previous versions.
One example of a board with this build had a blue component-side PCB.
I can only assume these are later manufacturing runs.
---------------------------------------------------------------------------------------------------
Transistor packages:
TO-92 common flat-face plastic package
TO-98 like a TO-92 with a round skirt at the bottom
TO-106 Small button head
---------------------------------------------------------------------------------------------------
Bias points
For ckt1, calc Q1 at VC1=3.4V
For ckt3,4, calc Q1 at VC1=3.2V
For ckt1, 3, 4 calc Q2 at VC2=3.05V
For the Nashville circuit, VC1=5.3V, VE2=5.9V
---------------------------------------------------------------------------------------------------
Interesting tread!
I do love the bosstone topology; I like the California version with bigger caps (22 to 47 nF) and no clipping diodes. Also I like to mix Si for q1 and Ge for q2.
Always been curious about the boss boost, there are not schematics on line, nor videos on YT or reviews... He said with sweaty hands :-)
I'm posting this schematic here because some photographs has been useful for perfboarding it. It's verified and gives some variety to a Boss Tone v1 that shares the same board.
(https://generaledefoutre.files.wordpress.com/2023/04/jordan_boss_boost_schematic-1.jpg)
Build it with two 2n3904 and didn't have the 2.2 megohm so i put two 1 megohm resistors.
Used 100k log pots as well, i put 100k lin on the schematic, assuming that it was the same pots in the Bosstone.
Just built another Bosstone (Nashville cct) as I couldn't get octave notes on a previous build (Russian diodes fv > 0.7V), even when i increased input/output caps. The new build was stock apart from switchable asymmetric clipping (1 Ge diode switched in/out of cct), this time with KD521A Russian silicon diodes (fv < 0.6V). Used low hfe transistors (< 150 i think?).
Nice, gnarly octave down notes at certain points around the fretboard, but these disappeared as soon as the Ge was switched in. More compression obviously, but it was interesting how the diodes affected the Bosstone in a simlar way to the Harmonic Percolator.
Quote from: Dan N on August 22, 2006, 08:50:50 PM
I built the CA version and must confess was disappointed. Good crackly fuzz, but quick gated sustain. Real old school in a bad kind of way.
I switched the PNP to an NPN ( e to ground, b in and c out) and this little guy came roaring to life! Pretty damn good fuzz. Fuzzy with plenty of bass and nice sustain.
[....]
hello from 2023! :)
just for curiosity's sake... and clarity's...
what Dan N talks about / what you talk about, Dan N,
involves some errors, right?
(I'm no expert)
first: that it sounds bad cause others love the circuit...
there may have been some glitch, like a bad transistor, right? -- or wrong? :) wrong transistor orientation using a socket, maybe?
2nd: connecting:"e to ground, b in and c out"
should have said "switch e and c"?
"c out" I can render meaning to but "b in" goes off the map, in my head :)
but does this even work like that? as simple as that?
sure, I've read this:
https://www.nutsvolts.com/questions-and-answers/semiconductor-sex-explained
and this:
https://barbarach.com/npn-to-pnp-transistor/
One of the errors that kept coming up was the 47pF cap on the Nashville circuit.
47pF is what is in the units, not 47nF or 47uF.
The "odd" transistor connection is actually well known. It's called a Sziklai pair.
https://www.theengineeringknowledge.com/introduction-to-sziklai-transistor-pair/
The addition of the BE resistor sets the operating current of the first transistor.
A Sziklai pair is sort of a like a Darlington. You will see extra BE reisistors on Darlingtons for the same reason.
In the Nashville circuit the Sziklai pair is acting like an NPN transistor.
There's an old post analyzing the finer points of this circuit. As I recall the effect of the 47pF cap was
analyzed and I seemed to remember something happens when the value is around 10nF (can't remember
if it was good or bad). It's some time back so you might have to update the image URLs.