Author Topic: Selmer Buzz-Tone...  (Read 15918 times)

LucifersTrip

Selmer Buzz-Tone...
« on: December 23, 2011, 01:45:18 AM »
I've finally got around to starting a Buzz-Tone and couldn't find any build reports here. Actually, if i did my search correctly, there's only one thread from 2004, with virtually no info at all.
http://www.diystompboxes.com/smfforum/index.php?topic=25976.0

It's of course similar to the FZ-1 & FZ-1A (same transistors)
http://experimentalistsanonymous.com/diy/Schematics/Fuzz%20and%20Fuzzy%20Noisemakers/Maestro%20FZ-1%20and%20FZ-1a.GIF
... but Q1 is not an emitter follower.

Is there anyone that built this that has notes or remembers any of the voltages to one that sounds good?





I'll report later if I have any luck...


thanx
always think outside the box

LucifersTrip

Re: Selmer Buzz-Tone...
« Reply #1 on: December 24, 2011, 11:18:49 PM »
...a little surprised no interest, especially since this is the pedal Syd Barrett used with early Floyd

Edit: This is the first fuzz I haven't been able to get to fire up (I'm getting a slightly muddy, dirty fuzz with high strings that decay with a slight fizz... a bit boomy and very loud with vol at 100%) in a really, really long time, though I honestly don't know what an original should sound like.

One quick question: Mathematically, is it possible (or at least realistic) to get Q3C voltage > .8v ?  I don't remember any other pedals with such small resistors across the base/collectors.

I have tried a ton of combos of gains & leakages in every position and .8v seems to be the max, though no one was able to help with voltages, so I really don't know what I'm shooting for yet...

thanx

« Last Edit: December 25, 2011, 03:46:24 PM by LucifersTrip »
always think outside the box

PRR

Re: Selmer Buzz-Tone...
« Reply #2 on: December 26, 2011, 01:02:24 AM »
> ...a little surprised no interest

Christmas. All the elves are busy.

> but Q1 is not an emitter follower.

It's a gain-of-2-or-less. And there is a 27K:11K divider in front. Not much different from an emitter follower. Actually lower gain: about 0.6.

Maybe that's a reason the other versions are more popular?

> This is the first fuzz I haven't been able to get to fire up

You must be pretty careful and very lucky.

You did note 3V not 9V??

One-finger voltage estimates:



> get Q3C voltage > .8v ?

Use hFE of 40 or less.

But why would you want >0.8V here?
« Last Edit: December 26, 2011, 01:04:45 AM by PRR »

LucifersTrip

Re: Selmer Buzz-Tone...
« Reply #3 on: December 26, 2011, 04:39:54 AM »
> ...a little surprised no interest

Christmas. All the elves are busy.

hahah...that is possible. Though, I've seen similar patterns with posts of other obscure vintage stuff.

Quote
> This is the first fuzz I haven't been able to get to fire up  


You must be pretty careful and very lucky.

"...in a really long time"
It's probably patience, persistence, attention to detail and excellent close-up vision. I've only built 75-85 different fuzzes, but no two identical, all working, and zero unfinished, broken or scrapped...and 100% on perf from schematics. It makes it insanely easy to troubleshoot and tweak since my perf builds can be virtually superimposed on top of the schematic.

Quote
You did note 3V not 9V??

yes

Quote
One-finger voltage estimates:



Thank you very much.

Quote
> get Q3C voltage > .8v ?

Use hFE of 40 or less.

You're right on the money. Q1/2/3 gains are 80, 120, 35 respectively. This gave me the best sound so far.

Quote
But why would you want >0.8V here?

I don't, really. I just wanted to eliminate the possibility that I screwed something up. If I know it's mathematically unrealistic >.8v, I won't waste any time trying. Your estimates are very close to what I got, so that's a comfort.
Also, I was expecting the obligatory "set the collector voltage to 1/2 the supply voltage, 1.5v" comment.

The other variants only "fire up" with a very leaky (300+ uA) Q3, but that didn't work for me here.

Thanx again for taking the time. I appreciate it.
« Last Edit: December 26, 2011, 04:04:52 PM by LucifersTrip »
always think outside the box

seedlings

Re: Selmer Buzz-Tone...
« Reply #4 on: December 27, 2011, 10:31:23 AM »
So how's it sound compared to FF?  Will you keep it or re-purpose?

CHAD

LucifersTrip

Re: Selmer Buzz-Tone...
« Reply #5 on: December 27, 2011, 04:00:12 PM »
So how's it sound compared to FF?  Will you keep it or re-purpose?

CHAD

This is a completely different type of circuit than a FF...no comparison. So far, I have, basically, a more bassy/muddy version of an FZ-1.

It could be close to how it's supposed to sound, but I don't think so. I'm going to continue to experiment & tweak.
always think outside the box

earthtonesaudio

Re: Selmer Buzz-Tone...
« Reply #6 on: December 27, 2011, 08:39:05 PM »
I would not be surprised if the original had a bypass cap across the 1k emitter resistor.  That would liven things up a bit.

LucifersTrip

Re: Selmer Buzz-Tone...
« Reply #7 on: December 27, 2011, 11:02:40 PM »
I would not be surprised if the original had a bypass cap across the 1k emitter resistor.  That would liven things up a bit.

It's doubtful, but I'll definitely give it a shot!

ironically, isn't that the 1K right there in front....



Edit:
I dropped a 22uF cap in there,  and earthtonesaudio, you got it right on the money! Thank you.
(also tried 4.7uF & 47uF and 22uF won)

Quick note: Prior to that, I was experimenting with Q2 & Q3's B-C resistors and originally got the best sound with 44K and 11K respectively. Unfortunately, when I increased Q3's B-C resistor to get the best tone, there was a significant increase in hiss.

Anyway, with that 22uF cap in there, I get the best tone with 15K-20K on Q2 (below 15K is dirty and muddier) and 500-1K on Q3 (~500-600 gives a nice thin bumblebee fuzz. I'll probably go with a 500 cutoff w/ 500 pot. increasing >2K adds hiss and starts to get a bit boomy). Since I didn't need to raise the B-C Q3, hiss is now to a minimum.

I'm now getting a much smoother, saturated fuzz, with reasonable sustain on all strings, no fizzy decays and only minimal hiss. There's no more muddiness or dullness and is easily worth boxing at this point.

Since I'm a completist, I will further experiment with transistors before finalizing. It's hard for me to believe that 35 hfe and -.24v will give me the best sound, but it's pretty damn good already.

Here's what I have with full vol & full fuzz:





« Last Edit: December 28, 2011, 01:36:18 AM by LucifersTrip »
always think outside the box

LucifersTrip

build report final: Selmer Buzz-Tone...
« Reply #8 on: December 30, 2011, 03:38:18 AM »
The final....

I tried various Q3's with higher gain and it sounded a little better with a higher gain (88) one...a bit hotter. I tried even higher (150) and it got worse...harsh and a bit broken up.  For a quick final test, I dropped a leaky one in there and the C voltage dropped to -.15v and gave me a dull, weak, junk tone.  

The depth pot was a little weak for the first 10K, so I'm going with a 10K pot there.

I re-tweaked the B-C resistor on Q2 by ear and kept coming up with 20-22K this time, so I threw the original 22K back in there.

I'm still surprised about the small value of the B-C resistor on Q3 and the C voltage, so I raised that B-C resistor again. If I increased it above ~ 3K it starts to really gets hissy, boomy, muddy and broken up (like a FF Q2 collector at 8v)...junk. The C voltage rose as I increased the B-C resistor, of course. I probably hit ~ -1.24v to -1.5v at the stock 15K, but as I just wrote, the tone was absolutely terrible....super hissy & boomy...unusable.

1.5K is at the point where it's just at the edge of too boomy. If I lowered the B-C resistor, it gets thinner, more trebly and trashy. It was usable down to ~ 500 ohm, so I went with a 500 + 1K pot.

So, the bottom line, only two big changes from the original: a 22uF cap across Q1's emitter resistor and a large reduction in Q3's B-C resistor.

Sounds like a loud FZ-1A with more bass.

Here's my final version:






always think outside the box

slim_blues_boy

Re: Selmer Buzz-Tone...
« Reply #9 on: December 30, 2011, 10:34:55 AM »
interesting, this might become my 'next project'  :icon_mrgreen:

LucifersTrip

Re: Selmer Buzz-Tone...
« Reply #10 on: January 17, 2012, 05:55:29 AM »
interesting, this might become my 'next project'  :icon_mrgreen:

go for it...but you better like electrolytics:



always think outside the box

earthtonesaudio

Re: Selmer Buzz-Tone...
« Reply #11 on: January 17, 2012, 07:01:53 AM »
Nice!  I like the floating resistors.

frank_p

Re: Selmer Buzz-Tone...
« Reply #12 on: January 17, 2012, 01:33:25 PM »

That is a cool built !


Solidhex

Re: Selmer Buzz-Tone...
« Reply #13 on: January 17, 2012, 03:22:36 PM »
  Its really just a crunchy slightly fuzzy booster. Not what I would consider a fuzz. I've had better luck with higher gain transistors. It does have some nice grunt to it though due to the huge caps.

LucifersTrip

Re: Selmer Buzz-Tone...
« Reply #14 on: January 17, 2012, 11:26:24 PM »
 Its really just a crunchy slightly fuzzy booster. Not what I would consider a fuzz.


not if you really set it up right and tweak it (did you hear it with the 22uf on Q1E and alter the B-C resistors?)....unless you don't consider an FZ-1 a fuzz, either.  It has an early fuzz sound...it's no Orpheum.

of course, with the mods, it's very possible that it sounds very different than the original. I wasn't able to find any good sound clips.


« Last Edit: January 17, 2012, 11:49:09 PM by LucifersTrip »
always think outside the box

Solidhex

Re: Selmer Buzz-Tone...
« Reply #15 on: January 25, 2012, 02:50:16 PM »
 Naturally I'm talking about the stock circuit. I've built it using RCA 2N2614's. Tried the original RCA 2N2613's and it was meh. I was told by someone who had access to an original that it sounded like ass as well. The emitter bypass cap is a good idea since the gain stages are set up for such low gain. There's a silicon version out there as well... http://www.diystompboxes.com/smfforum/index.php?topic=63332.0

LucifersTrip

Re: Selmer Buzz-Tone...
« Reply #16 on: January 25, 2012, 04:26:02 PM »
Naturally I'm talking about the stock circuit.

sounds cool...it wasn't clear since you posted immediately after my build report, aand I thought you may have tried it.

Quote
I've built it using RCA 2N2614's. Tried the original RCA 2N2613's and it was meh. I was told by someone who had access to an original that it sounded like ass as well.

as is very common with these types (1.5v, 3v FZ-1, etc), many of the originals didn't even sound great!

Quote
The emitter bypass cap is a good idea since the gain stages are set up for such low gain. There's a silicon version out there as well... http://www.diystompboxes.com/smfforum/index.php?topic=63332.0

yes, the Hofner is very similar. Though, jmusser actually subbed 2N5087's into the Selmer and got it working great:
http://www.diystompboxes.com/smfforum/index.php?topic=38842.msg275767#msg275767

I didn't initially refer to that build report since I was interested in getting a ge version to work...
always think outside the box

Chrisfromiowa

Re: Selmer Buzz-Tone...
« Reply #17 on: November 28, 2017, 01:07:49 PM »
interesting, this might become my 'next project'  :icon_mrgreen:

go for it...but you better like electrolytics:


I know this thread is a couple million years old, but how did yours turn out? Thanks
Better a live dog than a dead king.....
PKD

yeeshkul

Re: Selmer Buzz-Tone...
« Reply #18 on: November 29, 2017, 02:24:36 AM »
Guys is there an actual proof Syd Barrett used this pedal? It seems like people just copy/paste one article on their pages, feedeng the hype about it. When i listen to the Treble and Bass Mk2 amp itself, the sound is right there, no need for a fuzz box.

Listen to this: https://www.youtube.com/watch?v=YIER8JSz9sA

Just asking, no hard feelings :)
« Last Edit: November 29, 2017, 02:43:15 AM by yeeshkul »
I don't believe anything i haven't measured with my RoHS friendly Chinese multimeter.

LucifersTrip

Re: Selmer Buzz-Tone...
« Reply #19 on: November 29, 2017, 03:23:53 AM »
interesting, this might become my 'next project'  :icon_mrgreen:

go for it...but you better like electrolytics:


I know this thread is a couple million years old, but how did yours turn out? Thanks

I wrote above...It was cool enough to box, kind of like a louder, bassier Fz-1a. Worth it for me since Fz-1a's are one of my favorites. But, if you haven't built an Fz-1a or variant, I wouldn't build this one yet.
always think outside the box