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WIGGLING 'LITE' IN GUEST MODE

Buchla Clone 259r
MUFF WIGGLER Forum Index -> Buchla, EMS & Serge Goto page 1, 2  Next [all]
Author Buchla Clone 259r
Don T
I'm not sure if this is the correct place to ask, so mods feel free to move/delete/laugh at uncontrollably...

Is there anyone that lives in the Atlanta area that has a 259r built exactly per Roman's BOM? I would very much like to compare my 259r that was built with all vintage semiconductors, as correct to the original 259 as I could possibly get. I'd like to see if all the scavenger hunting I did for the original parts was worth it!

It would be a bonus if we could record the two side-by-side and share here!
J3RK
That would be pretty cool to see/hear. I like the pics of your build.
batchas
J3RK wrote:
That would be pretty cool to see/hear. I like the pics of your build.

+1
bsilverberg
Hey Don, check your pm's/email. I've got what you're looking for.
Don T
bsilverberg wrote:
Hey Don, check your pm's/email. I've got what you're looking for.


Ben, found the messages, I'll be in touch soon! Right now, the melatonin is finally kicking in! zombie
sempervirent
Don T wrote:
It would be a bonus if we could record the two side-by-side and share here!

Would definitely be interested to hear that...
Don T
sempervirent wrote:
Don T wrote:
It would be a bonus if we could record the two side-by-side and share here!

Would definitely be interested to hear that...


We're working on it! cool
Don T
Ok folks, some results:

First, a big thank you to fellow wiggler bsilverberg for hosting me, and for providing the "standard BOM" 259r!

To remind everyone, bsilverberg's 259r is built with the "standard Roman BOM", while mine is built with all vintage semiconductors, part numbers and specs per the original Buchla schematics. I'll refer to them hereafter as "Standard" and "Vintage".

[EDIT] The "Standard" version is built with all 1% tolerance metal film resistors, whereas the "Vintage" version is built with 5% tolerance carbon film resistors, except where 1% resistors are called for in the schematic, RN55D and RN55C resistors occupy those spaces, just as they would have in the original.

I'm going to post a couple scope screen shots and a short vid of our test. We actually played around for a couple hours with the two after we made these pics and the vid, but for right now, I'm just going to post them as-is, without comment, and let everyone make any observations/comments they'd like before I open my mouth with my opinion.

First off, two screen shots of the main outs of both, no modulation or Timbre adjustments of any kind, just the raw Sine out.






Yes, with identical scope settings, the amplitude of the "Standard" version was higher than the "Vintage" version, that's all I'll say for now...

And now the video. Yes, this is an iPhone video (5S), but still worth a listen. I recommend decent headphones or decent speakers:



Both 259s are playing simultaneously. The Timbre control is being swept from nothing to maximum. The Symmetry and Harmonics controls are set to minimum on both. You'll see the "Standard" 259r sweep through the Timbre control first, followed by the "Vintage" 259r

Let us know what you guys think!

bsilverberg, feel free to add/jump in at any time!
Orwell
With you ears, ha, what did you guys think of the different versions ?
scottmoon
thumbs up
Peake
On the oscilloscope sweep, I prefer the second version.
bsilverberg
In the room I can tell you the difference was profoundly significant. The standard 259 sounded good, but the vintage component outfitted 259 sounded amazingly rich, complex, "meowy," and musical with a character you'd gladly pay dearly for. We (literally) shook the walls sweeping it at a slow rate across the spectrum. Sounded very musical, we both commented how it hints at Moog in flavor, yet still distinct. Having experienced it in person, I would be inclined to build it again, with vintage components. It's THAT good. Hat tip to Don for an amazing job well done!!
Don T
Peake wrote:
On the oscilloscope sweep, I prefer the second version.


That was the one with all vintage components!

bsilverberg wrote:
In the room I can tell you the difference was profoundly significant. The standard 259 sounded good, but the vintage component outfitted 259 sounded amazingly rich, complex, "meowy," and musical with a character you'd gladly pay dearly for. We (literally) shook the walls sweeping it at a slow rate across the spectrum. Sounded very musical, we both commented how it hints at Moog in flavor, yet still distinct. Having experienced it in person, I would be inclined to build it again, with vintage components. It's THAT good. Hat tip to Don for an amazing job well done!!


Thanks for the kind words, Ben!

For the good of the order:
I went into this expecting a very subtle difference, and I was prepared to be disappointed that there might be no difference at all. I was also expecting that most of the difference could be attributed to nothing more than random variations in semiconductors and/or vactrols.

What I was not prepared for was the difference we got!

To start with, the Sine waves between the two looked slightly different on the scope, and the difference looked subtle. The "Standard" 259r is ever-so-slightly triangle-ish in shape compared to the "Vintage" 259r, which looks more "mathematically correct" in shape. The "Standard" differs most on the rise and fall portion of the wave. It is almost a straight line on the rise and fall, whereas the "Vintage" 259r curves almost all the way down the 0V line on both the rise and fall. Yes, the difference is indeed audible. Both Ben and I agreed that while both sounded very good, the "Vintage" unit sounded more pure. It doesn't come cheap though. Finding, then buying, enough older 2N4339 JFETs to pick out the magical one that has an Idss between .7 and 1.2mA may be more than what some people want to spend. I bought two bags of 10 for about $30 each (on two different occasions), and each bag of 10 yielded 4 that met the spec for the Sine shaper circuit. I had a few of J3RK's 258j boards to build, plus a 208r V2, so the expense was more than worth it for me.

Then we started playing with the Timbre controls...

WOAH! woah

I wasn't expecting the difference to be that big, but it was! CA3160 isn't an easy chip to find, and may cost you a minimum of $5 each, but the difference was too big to ignore. The short video posted above was the second time that Ben and I swept the Timbre controls. It was such a shock the first time that I grabbed my phone and started recording, thinking "Man, the guys aren't going to believe this!". The recording, again, was made with an iPhone 5S, and the sound was coming through Ben's Rokit monitors. We got caught up in playing around with both 259s, and Ben decided he wanted to hear how low in frequency some of the sounds were getting, so he hooked up the mixer to his his stereo pair of Cerwin-Vega speakers. The difference became even more profound!

Caveat: As will all things in the world of analog electronics, you results may vary! Another variable worth noting, while the "Standard" 259r used whatever PN3565 transistors that Mouser provided, the "Vintage" 259r not only used old 2N3565 transistors in the TO-106 (glob top) package, they were also precisely matched for Vbe in the cores of both the main oscillator and the modulation oscillator. The Moog transistor matching circuit was used.

[EDIT] Both 259rs were indeed calibrated, and both had Dave Brown's timing cap mod installed on the modulation oscillator.

Now the question remains, how would the "Vintage" 259r compare to an original 259?

Anyone in ATL got a REAL 259? cool
djangosfire
Thanks for sharing guys! Guinness ftw!

One thing that I find when building the 259r modules, is that each build will vary in tone..BUT the 2x key points:

1 - test and choose a good J201 for a good sine on the principle VCO.

2 - you NEED to to have a huge pile of LS3958's on hand.... this is the component that will make the timbre shaping so great... and it often is about every one in ten that will be the winner.

Also, since I am not an engineer - just a builder that loves sound.... so yes, I calibrate and test with a scope on hand, but in the end I let my ears decide.

Thank you again - great work!!!!

Cheers,
- Adam
SynthBaron
djangosfire wrote:

1 - test and choose a good J201 for a good sine on the principle VCO.

2 - you NEED to to have a huge pile of LS3958's on hand.... this is the component that will make the timbre shaping so great... and it often is about every one in ten that will be the winner.


It seems very few manufacturers bother to follow the original component selection procedures when building clones. It's always a thought in the back of my head of "did they actually build this right"...
Don T
djangosfire wrote:

2 - you NEED to to have a huge pile of LS3958's on hand.... this is the component that will make the timbre shaping so great... and it often is about every one in ten that will be the winner.


Interesting. I wonder if Idss or Vgs is the relevant factor involved. Logic would indicate if only 1 out of 10 hits the "sweet spot", then it's a value that falls at one extreme or the other on the spec sheet, and not the average. I'd be interested to get readings on the LS/2N3958 transistors that have the best response in this circuit vs the ones that do not!


djangosfire wrote:

Also, since I am not an engineer - just a builder that loves sound.... so yes, I calibrate and test with a scope on hand, but in the end I let my ears decide.


Same here, and thanks for the kind words!
malnatim
very interesting! thank you don t.

if the J201 wasn't selected in the standard build it's probably not fair to compare it's sine to that of a build with selected 2N4339.

(assuming the 259 is similar to the 258) there's 2 pairs of resistors and a pair of diodes in the sine shape section that should be matched. this is no real expense and only takes 5mins.

in 291 the 2N3958 should be selected for Idss >3ma to avoid distortion. maybe a lower Idss is suited to a wavefolder for saturation of the transistor(s)? it would make good use of all the 2N3958 rejected from 291 builds. it sounds like the kind of thing a great designer might do. i don't really have a clue! maybe someone who knows can chime in here.
Musicology of Dreams
Modern 21 century diy synth are at majority made with metal 1% resistors
old Buchla and 70's analog synth's use carbon resistors in all modules builds with few metals only...something to meditate....
Don T
Musicology of Dreams wrote:
Modern 21 century diy synth are at majority made with metal 1% resistors
old Buchla and 70's analog synth's use carbon resistors in all modules builds with few metals only...something to meditate....


You may have missed it, but my 259r was indeed built with 5% carbon film resistors everywhere 1% were not called for.

malnatim wrote:

if the J201 wasn't selected in the standard build it's probably not fair to compare its sine to that of a build with selected 2N4339.

(assuming the 259 is similar to the 258) there's 2 pairs of resistors and a pair of diodes in the sine shape section that should be matched. this is no real expense and only takes 5mins.


That's just it, and why I do consider it fair, the standard BOM doesn't call for any selected or matched components. Should it? Maybe. Does it? No, which is one reason for highlighting the difference like we did.

If anyone did indeed build their 259r with a J201 that was selected with an Idss of .7 to 1.2mA, please feel free to post a scree shot of your Sine wave!
malnatim
i've built two 258r, two 291r and some 100 clones with the orig transistors. i compared to a 258r with the modern substitutes and it sounded different to my builds. i didn't build it so don't know if any of the components were selected where they probably should be. roman's boms don't specify to select components, but i think you should. ie vactrols in 207 / 292. i found it's important to select the dual JFETs in 291 for Idss >3ma. being out of range made a greater difference than 2N3958 or LS3958. i think there are also tweaks that aren't mentioned in the schematics. i guess there were likely build notes that we don't have.

i've got some 2N3958 and 2N3565 left over that i might try in my 259r. i didn't build it so not sure about the components selection. i think maybe the 3rd pair of 2N3565 (Q12+13) on page 4 of schematic might also benefit from being matched (the other 2 pairs in the oscillator cores do need matching). i think the pair of 1K and pair of 4k7 resistors near Q12+13 might also benefit from being matched. it's not really much bother to try. maybe someone who really understands the schematic give their opinion?

i'll leave the that340 as i don't want vintage quality tracking.
i'll try a 2N4339 (Idss .7-1.2mA). i'd guess that with selected J201 and matched diodes and resistors in the sine shaper you could get a decent sine. i used 2N4339 in my 258r builds and i used the waveforms on mark verbos' blog as reference. i'm really happy with them.
http://buchlatech.blogspot.co.uk/2009/01/funny-waveshapes.html
has anyone got the 258 scope shots that are now dead links (synthtech) that they could please share?

i'd like to try CA3160. i'd guess that maybe the wavefolder might be the place with most scope for audible differences between the org and replacement components. djangosfire mentions about 1 in 10 LS3958 sounding great. that's approx that ratio of Idss >3ma that i found. so, maybe they should be selected as for 291?
Don T
Fellow wiggler delayed asked about the differences in the BOM for my build vs. the standard build, so I thought I'd post the answer here in case anyone else was interested.

IC1, IC3 - TL062
All other places calling for TL072, TL082 was used.
IC36, IC37, IC38, IC39, IC40 - CA3160
IC11, IC13, IC15 - omitted
Q1, Q5 - KC-811 (AD-811) used for the NPN section, [EDIT]: 2N4937 used for the PNP section. On the data sheets, [EDIT]: 2N4937 differs mainly from AD-821 only in Hfe range.
Q3, Q4 - 2N3565 matched pair
Q12, Q13 - 2N3565 matched pair
Q7, Q8 - 2N3565
Q9 - 2N4339, selected for Idss between 0.7 and 1.2mA
Q10 - LS3958 (Yes, one of the new ones!)
PTC1, PTC2 - Tel Labs Q81 1K 1% (probably not critical, but I just happened to have two of these from a dead synth and used them.)
All other resistors, unless designated 1% metal film in the original schematics, are 5% carbon film.
R* - No resistor used.

For capacitors, I mainly used whatever I had on hand that was the correct type and value (Mostly salvaged from old synths and audio gear), with the exception of the 220pF caps, I used silver-mica, under the assumption that decent caps would work well in those positions. Maybe, maybe not. In many of the places calling for a surface-mount tantalum cap, I surface-soldered thru-hole electrolytic caps. Why? After years of working on dead ARPs, I just tend to avoid tantalum, I'm probably superstitious in this area...

Also, I added Dave Brown's modification that switches in a 0.47 film cap into the circuit when the low frequency range switch is active on the Modulation Oscillator. I tried the Modulation Oscillator out a couple days without this mod installed, and decided it was essential for correct low frequency wave shape, so, thanks Dave Brown!

A photo of the back, taken from the 259r build thread:


[EDIT]: This photo was taken before adding Dave Brown's mod.
Don T
NOTE: My previous post was edited to correct a typo on a part number. The part used is 2N4937, not the part where I transposed a couple digits. Making this post so that you guys will notice!

Sorry if anyone was confused by my error.
richard
Thanks for this thread. I have been lucky to play 4 original 259s, which sounded a little different from each other and are easily the most remarkable VCOs I have ever had my hands on. I realise that if I do go for some clones one day I would need to shift my expectations of them, and/or spend a great deal of time and money getting them close.
cygmu
Bit of a thread-bump, but this seemed the appropriate place for this question.

I've just been looking at the build docs for the Feedback Two59 Eurorack module which is a redesign of the 259. https://www.muffwiggler.com/forum/viewtopic.php?t=169991&postdays=0&po storder=asc&start=25

The thing that interested me was that the build doc recommends not only trying a number of 2n4339s in the sine shaper circuit, but also varying the value of accompanying resistors. This makes sense in light of the importance of selecting for Idss.

Has anyone tried this on a 259r? I guess it is R104 and R105 to look at. Apparently in the Two59, some builds work best with 150k resistors rather than the 33k in the standard BOM. I'm wondering if varying the resistor value can make more FETs usable, or get even better results out of FETs with already good Idss.
babybeluga
Hi guys - long time (years) 'lurker' here..

I find this to be a very interesting discussion indeed & that the careful selection of certain components / use of NOS parts may be able to nudge a 259 build further in the direction of an original module... Or, actually probably even a better outcome than vintageness: achieve improved results generally with the build as opposed to plunking in off the shelf & untested parts..

No doubt you've all seen this below clip of an original 259 (supposedly) - running through some eurorack modules. The richness & tonal complexity is really fascinating and, as far as I can tell from youtube adventures, is somewhat different to the modern 'clone' builds which seem to tend to sound more 'clean' and perhaps a bit less like a wild bronco :-0 ..

It must be said that the djangosfire builds sound awesome! (Which lends weight to the idea of careful selection of key components..)

And further - thanks to everyone generally for all their contributions of hard won info around here..



https://www.youtube.com/watch?v=RO5qRyzYZXk
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