SRV in a Box?? (maybe)

[markm]

Please notice there is an error in both layouts (linked in first and third posts). Opamp pin #3 has no resistance to Vcc/2, and is capacitively coupled only.

That's how the schem reads for the SRV version is it not?
I corrected the standard TS808 in the gallery.
Thanks!

[RLBJR65]

Thanks Mark! Thats another nice looking layout.
Looks like a great site too. Google translator didn't do to good a job for me I'll have to try a couple others.

[Eb7+9]

thx for posting the layout ...

in '97 two producers asked me to collate a bunch of home-reversed schematics and original circuits ideas in a book for them to take to the crapper in the late of nite ... it was called "Rainbow of Sound" and I sold about 20 copies by word of mouth - mainly to engineers who weren't into spending time on the net ... it was a rough fake-type of affair that included some theory on the Univibe, the TS808, the MutronIII, lots of mods and a bunch of other stuff for filler ... one or two members on this forum got a copy of the book in the spring of '98 ...

my original target with the TS808 was specifically to elliminate some of the mud from the response and my theory at the time was that it could be made clearer (transient wise) by removing what I considered to be redundant caps in the signal path ... following the idea that the best cap to use is no cap at all ... to answer the question of redundancy I did a worse case variance analysis of the circuit against offset mechanisms and found that it could live somewhat comfortably inside the rails yielding little loss in headroom throughout and therefore preserved the dynamic character of the pedal except for the drive range which was intentionally increased ... the tonal aspects where left invariant as much as possible ...

here's the "offset" analysis for the TS808 and "very" rough vero layout chart with parts list from the book ... they were on my website at one point

http://www.lynx.net/~jc/vivaTSmods1.gif
http://www.lynx.net/~jc/vivaTSmods2.gif
http://www.lynx.net/~jc/vivaTSmods3.gif

the cloned result became what I called the SRV Special overdrive - of which I sold about 30 units worldwide between '98 and '05 ... many of them where done in plain Hammond boxes ... the picture below shows my original re-boxed TS-5 with the mods (left) - which I still gig with - the one in the middle was done for a genius buddy in Winnipeg (that one features a 10uF cap at the input like in the layout) ...



below is a link to a clean re-draw of the original schematic from a few years ago ... notice the input cap in this schem is stock (0.02uF) I prefer that to the blathery 10uF ... but some guys I know who play hot-rodded Supers like that a lot ... seems the layout values was a reversal of one the of the few I did with a big input cap, just like the one that came up on ebay last year ... I used 510k bias resistors in all the units, the only difference is the 10 ohm resistor at the output which I never used ...

http://www.lynx.net/~jc/SRVspecial schematic.gif

one thing that's interesting to note after all this was the presence of some residual mud after removing the four signal path caps - an interesting clue in itself,is it due to the remaining caps or something else going on outside of cap gloss ... this lead to a further step in the simplification which I explored this winter and yielded a new design that has the transparency of a piece of wire when the diodes are not clipping - very nice ! ... who knows, maybe the DIY community will soon be ready to embrace a substantial paradigm shift in signal path methodology if I can say so ... however, for sake of purists, the new design does take the idea into an area of performance that doesn't quite sound like the TS808 anymore, it's a new beast really and so can't be compared directly

just to answer a side point raised here - you won't get SRV just from this pedal - obviously, it's a tweaked 808 ... the idea was not to clone SRV's tone with just the pedal but rather give a better performing version of the topology without "mucking" it up in the process - aside from the gain control difference the tweaks are subtle and no surprise that many of the guys I built some for were older blues-rock players ... now, aside from SRV's PU's and heavy strings there's a few things that were done to some of his key Fender amps to get that extra inch of richness which is very much part of his signature tone ... if you read the tone quest report where Cezar is interviewed he drops a hint on what that last step is about ...

[puretube]

that largish 10µ at the high impedance got me ?-ing, too...

maybe it un-biases the directcoupled 1st opamp a little at note-attack?

[jlullo]

Here's the schematic link;

http://matsumin.gozaru.jp/contents/jisaku/ts_srv/sch.BMP

mark,
when i click the link, i get an error page... is this just me?

[alderbody]

right click / save target as

[black mariah]

Just thought I'd let everyone know that 13's aren't that heavy. I used to use them all the time. Really only stopped because my tiny-ass hands refused to let me use them anymore. Carpal tunnel is fun!

[MartyMart]

Good stuff JC
I've found that the 0.22uf to ground following the 1k off first half of IC, to be a real "tone sucker" !
Reducing that to 0.1uf or 0.047uf really opens up the tone AND makes the tone control much more
useful too - it has something to "get hold of" when this is done.
That, along with a couple of known gain changes and using MPSA18's makes a huge difference.
MM.

[searoad]

Good stuff JC
I've found that the 0.22uf to ground following the 1k off first half of IC, to be a real "tone sucker" !
Reducing that to 0.1uf or 0.047uf really opens up the tone AND makes the tone control much more
useful too - it has something to "get hold of" when this is done.
That, along with a couple of known gain changes and using MPSA18's makes a huge difference.
MM.

for the 0.22uf see GGG's ITS8 mod text
there is a mod suggested by aron to take the cap off (not jumper it iiirc)
which ive done on my sd1 to get a brighter sound.

[markm]

Thanks Eb7+9! 
Strange how this circuit has suddenly been taken seriously since your post.

[MartyMart]

Thanks Eb7+9! 
Strange how this circuit has suddenly been taken seriously since your post.

Mark, I didn't think that there was anything remotely "funny" about the thread, I just needed to see
a schematic before I could "see" any differences    ( just the way I think, not in a layout way at first ! )
And a BIG THANKS from me for your "stellar layout work" - much appreciated mate

Marty.

[markm]

No offense taken Marty, I understand completely.
You've helped me numerous times and I thank you for that.
None of my comments are directed at you or anyone else directly. 

[Dragonfly]

thx for posting the layout ...

in '97 two producers asked me to collate a bunch of home-reversed schematics and original circuits ideas in a book for them to take to the crapper in the late of nite ... it was called "Rainbow of Sound" and I sold about 20 copies by word of mouth - mainly to engineers who weren't into spending time on the net ... it was a rough fake-type of affair that included some theory on the Univibe, the TS808, the MutronIII, lots of mods and a bunch of other stuff for filler ... one or two members on this forum got a copy of the book in the spring of '98 ...

my original target with the TS808 was specifically to elliminate some of the mud from the response and my theory at the time was that it could be made clearer (transient wise) by removing what I considered to be redundant caps in the signal path ... following the idea that the best cap to use is no cap at all ... to answer the question of redundancy I did a worse case variance analysis of the circuit against offset mechanisms and found that it could live somewhat comfortably inside the rails yielding little loss in headroom throughout and therefore preserved the dynamic character of the pedal except for the drive range which was intentionally increased ... the tonal aspects where left invariant as much as possible ...

here's the "offset" analysis for the TS808 and "very" rough vero layout chart with parts list from the book ... they were on my website at one point

http://www.lynx.net/~jc/vivaTSmods1.gif
http://www.lynx.net/~jc/vivaTSmods2.gif
http://www.lynx.net/~jc/vivaTSmods3.gif

the cloned result became what I called the SRV Special overdrive - of which I sold about 30 units worldwide between '98 and '05 ... many of them where done in plain Hammond boxes ... the picture below shows my original re-boxed TS-5 with the mods (left) - which I still gig with - the one in the middle was done for a genius buddy in Winnipeg (that one features a 10uF cap at the input like in the layout) ...

below is a link to a clean re-draw of the original schematic from a few years ago ... notice the input cap in this schem is stock (0.02uF) I prefer that to the blathery 10uF ... but some guys I know who play hot-rodded Supers like that a lot ... seems the layout values was a reversal of one the of the few I did with a big input cap, just like the one that came up on ebay last year ... I used 510k bias resistors in all the units, the only difference is the 10 ohm resistor at the output which I never used ...

http://www.lynx.net/~jc/SRVspecial schematic.gif

one thing that's interesting to note after all this was the presence of some residual mud after removing the four signal path caps - an interesting clue in itself,is it due to the remaining caps or something else going on outside of cap gloss ... this lead to a further step in the simplification which I explored this winter and yielded a new design that has the transparency of a piece of wire when the diodes are not clipping - very nice ! ... who knows, maybe the DIY community will soon be ready to embrace a substantial paradigm shift in signal path methodology if I can say so ... however, for sake of purists, the new design does take the idea into an area of performance that doesn't quite sound like the TS808 anymore, it's a new beast really and so can't be compared directly

just to answer a side point raised here - you won't get SRV just from this pedal - obviously, it's a tweaked 808 ... the idea was not to clone SRV's tone with just the pedal but rather give a better performing version of the topology without "mucking" it up in the process - aside from the gain control difference the tweaks are subtle and no surprise that many of the guys I built some for were older blues-rock players ... now, aside from SRV's PU's and heavy strings there's a few things that were done to some of his key Fender amps to get that extra inch of richness which is very much part of his signature tone ... if you read the tone quest report where Cezar is interviewed he drops a hint on what that last step is about ...

One of the most interesting things about this thread is that if Mark had posted the schematic originally, it is likely that would never would have had the benefit of reading the post I just quoted.

Hmmm.

[QSQCaito]

thx for posting the layout ...

in '97 two producers asked me to collate a bunch of home-reversed schematics and original circuits ideas in a book for them to take to the crapper in the late of nite ... it was called "Rainbow of Sound" and I sold about 20 copies by word of mouth - mainly to engineers who weren't into spending time on the net ... it was a rough fake-type of affair that included some theory on the Univibe, the TS808, the MutronIII, lots of mods and a bunch of other stuff for filler ... one or two members on this forum got a copy of the book in the spring of '98 ...

my original target with the TS808 was specifically to elliminate some of the mud from the response and my theory at the time was that it could be made clearer (transient wise) by removing what I considered to be redundant caps in the signal path ... following the idea that the best cap to use is no cap at all ... to answer the question of redundancy I did a worse case variance analysis of the circuit against offset mechanisms and found that it could live somewhat comfortably inside the rails yielding little loss in headroom throughout and therefore preserved the dynamic character of the pedal except for the drive range which was intentionally increased ... the tonal aspects where left invariant as much as possible ...

here's the "offset" analysis for the TS808 and "very" rough vero layout chart with parts list from the book ... they were on my website at one point

http://www.lynx.net/~jc/vivaTSmods1.gif
http://www.lynx.net/~jc/vivaTSmods2.gif
http://www.lynx.net/~jc/vivaTSmods3.gif

the cloned result became what I called the SRV Special overdrive - of which I sold about 30 units worldwide between '98 and '05 ... many of them where done in plain Hammond boxes ... the picture below shows my original re-boxed TS-5 with the mods (left) - which I still gig with - the one in the middle was done for a genius buddy in Winnipeg (that one features a 10uF cap at the input like in the layout) ...

below is a link to a clean re-draw of the original schematic from a few years ago ... notice the input cap in this schem is stock (0.02uF) I prefer that to the blathery 10uF ... but some guys I know who play hot-rodded Supers like that a lot ... seems the layout values was a reversal of one the of the few I did with a big input cap, just like the one that came up on ebay last year ... I used 510k bias resistors in all the units, the only difference is the 10 ohm resistor at the output which I never used ...

http://www.lynx.net/~jc/SRVspecial schematic.gif

one thing that's interesting to note after all this was the presence of some residual mud after removing the four signal path caps - an interesting clue in itself,is it due to the remaining caps or something else going on outside of cap gloss ... this lead to a further step in the simplification which I explored this winter and yielded a new design that has the transparency of a piece of wire when the diodes are not clipping - very nice ! ... who knows, maybe the DIY community will soon be ready to embrace a substantial paradigm shift in signal path methodology if I can say so ... however, for sake of purists, the new design does take the idea into an area of performance that doesn't quite sound like the TS808 anymore, it's a new beast really and so can't be compared directly

just to answer a side point raised here - you won't get SRV just from this pedal - obviously, it's a tweaked 808 ... the idea was not to clone SRV's tone with just the pedal but rather give a better performing version of the topology without "mucking" it up in the process - aside from the gain control difference the tweaks are subtle and no surprise that many of the guys I built some for were older blues-rock players ... now, aside from SRV's PU's and heavy strings there's a few things that were done to some of his key Fender amps to get that extra inch of richness which is very much part of his signature tone ... if you read the tone quest report where Cezar is interviewed he drops a hint on what that last step is about ...

One of the most interesting things about this thread is that if Mark had posted the schematic originally, it is likely that would never would have had the benefit of reading the post I just quoted.

Hmmm.

Good optimistic point by taking the good part and leaving the rest apart.

It's good to see half of the glass empty

[Dragonfly]

Good optimistic point by taking the good part and leaving the rest apart.

It's good to see half of the glass empty

Actually, I just found it to be quite an interesting post.