Boss - SD-1 Timmy, Landgraff, CJOD, BBOD, BMOD

new_anuzzerone · Post by **new_anuzzerone** » 05 Feb 2010, 21:58

I found a cheap SD1 today. There´s a 4558DD inside, which is considered to be the high-gain version of the 4558 op-amps.

Do you leave it untouched or do you change it to a different one? I got to order some stuff, so I would order some different op-amps alltogether...

what about the OPA.... / burr-brown? Recommended to stick inside this pedal or not?

tia, regards

mictester · Post by **mictester** » 06 Feb 2010, 03:14

new_anuzzerone wrote:I found a cheap SD1 today. There´s a 4558DD inside, which is considered to be the high-gain version of the 4558 op-amps.

Errr.... No. The "DD" version is just a slightly better spec than the basic "D" - slightly lower noise and wider temperature range.

The 4558 (in all its' versions) is an excellent op-amp for the clipping part of a pedal since it recovers nicely from overload. The ONLY reasons it was chosen for the Tubescreamers and similar pedals is that it was bipolar (so recovered from overdrive well and didn't lock up if the output hit the rails) and most of all because it was the CHEAPEST DUAL OP-AMP AVAILABLE!!! There's no "magic" or "mojo" about it - almost any bipolar dual will work well (try the LM833 for lower noise or the NE5532 for more harmonics)!

I used to buy 4558s in Japan for (roughly) $0.018 each (500 off price). Yes, really - under 2¢ each!!! If I could justify buying more (5000+) I could get them for $0.008 each. The transistors in the Tubescreamers often cost more (2SC1815Y was $0.022 at 1000 off, 2SK30A was $0.019 at 1000 off). The most expensive parts of those things were the housings, control knobs and the jack sockets. The PCB cost (roughly) $0.45 fully populated and tested. The hardware was almost $1.22!

Word of warning: Please don't get ripped off by people selling NOS op-amps at silly prices. If you don't believe me, build two quick Screamer boards with identical components apart from the op-amps. Try a NOS one if you must. Try some of the Philips and National ones. The only differences you'll possibly hear are in the noise and the treble content. Remember - the gain of the circuit is determined by the resistor ratios around the op-amps - not by the ICs themselves!

kareemk · Post by **kareemk** » 06 Feb 2010, 06:32

i replaced the stock DD in my cheap pedal with a D and i must say it sounds better now.. (with some capacitor changes)

mictester · Post by **mictester** » 06 Feb 2010, 07:24

kareemk wrote:i replaced the stock DD in my cheap pedal with a D and i must say it sounds better now.. (with some capacitor changes)

The capacitor changes will make the difference (you will have changed the frequency response). Changing the IC from a "DD" to a "D" will make no audible change whatsoever, except slightly increase the noise.

kareemk · Post by **kareemk** » 06 Feb 2010, 08:21

i did the changes as two stages... opamp change was done independently and i'm pretty sure it changed something. (before it i only used the pedal at max drive, now i get decent levels of dirt at all other stages of the drive knob)

new_anuzzerone · Post by **new_anuzzerone** » 06 Feb 2010, 13:12

thx for the answers.

@mictester: I´m a non-believer to all this mojo crap. After all, I´ve changed some ds and dds an l702s aso. and I never heard a change in sounds. I heard some major differences in changing all the caps in a TS-5 to same values but using panasonic smf caps. The sound was definetly better, imho.

I´ve jut read in the original post, that there were some recommended chips. Sorry....reading with your eyes open is a major advantage

For me it´s like any rumour: you got to have something to believe in.

thx for your hints

new_anuzzerone · Post by **new_anuzzerone** » 16 Feb 2010, 18:08

Recieved my SD-1 yesterday and converted it to your LPE specs.

D3 - 1n4001- remove and jumper (it's said removing this makes the pedal sound fuller)

D3 was already jumpered in my pedal, as well as R41 - you mentioned it!

I put a JRC072D inside and it sounds really great! Gonna try the other ICs as well.

THX for your posting!

roseblood11 · Post by **roseblood11** » 16 Feb 2010, 22:37

I still don´t understand, why anybody mods a SD-1 to LPE specs - it´s some work to do on a very cheap pcb.
And as long as you don´t remove the buffers and the electronic switching, you won´t end up with a LPE.

Building an Eternity from scratch on veroboard costs far less than 15€ and doesn´t take more time than the mod...
Those, who don´t want to do all the drilling etc. could use the enclosure of an old pedal - maybe that´s the cheapest solution, too.

new_anuzzerone · Post by **new_anuzzerone** » 16 Feb 2010, 23:28

Does there exist any plan bout the eternity? Has it been posted here?

For me, it´s much easier to mod an existing pedal, than building one from scratch....maybe someday, I´ll get to build one,....maybe

If you got a link, where I can find the plans, plz let me know, drop me a pm,...what else...

tia, regards

roseblood11 · Post by **roseblood11** » 17 Feb 2010, 13:24

use the search function...

https://www.freestompboxes.org/viewtopic ... l+eternity

And have a look at the gallery at diystompboxes.com, for some more veroboardlayouts.

Everything else you need to know to build a pedal from scratch is:
a) external wiring - search for the file "offboard wiring" at tonepad.com, amongst the FX projects
b) drilling the enclosure, painting etc

new_anuzzerone · Post by **new_anuzzerone** » 17 Feb 2010, 23:52

"search function"? what´s that?

*d´oh*

anyway, thx!

Silvestre · Post by **Silvestre** » 14 Oct 2010, 03:47

analogguru wrote:Don´t forget to change the tone-control. Since I don´t have the time to draw that up, here are the steps for the (non-mojo) basic Jones-mod:

1.) Remove R5 - R9, C2 - C6, D4 - D6, IC 1
2.) place a jumper wire instead of D5
3.) assemble a socket for IC1
4.) assemble R5 = 10k, R6 = 1k, R7 = 1k, R8 = 220 Ohm, R9 = 1k
5.) assemble C2 = 100n, C3 = 220n, C4 = 220n, C5 = 220n, C6 stays empty
6.) solder a 10k resistor in parallel to C4
7.) assemble the 2 red 5mm LED´s in D4 and D6
8.) take a chip of your choice (OPA2134) and plug it into the socket.

Now you have a (non-mojo) Jones-SD-1 and saved more than $1.450,--...

analogguru

Hello,

A few weeks ago was looking for diferences between the Boss SD1 and the TS808 circuitry to find which things to change to do a sort of conversion from the first to the second one.

And now, reading this post about what Clay Jones' Mod would be, i get the idea (i might be wrong, and would thank a lot any correction of my posible beginner mistakes) that this Clay Jones thing shares a few things with the TS808. So, in Clay Jones we would have:

R7, R8 & R9, and C4 & C5 changed from stock SD1, if not to fit the values of the TS808, fitting them any other way.
C6 removed the same as i would do to fit the SD1 to the schematic of TS808

Would you be so kind to tel me if i have missed anything?

What's your opinion about these similarities?

To my limited point of view, they (TS808 and Jones' Mod) are nearly the same with a softer clipping section, isn't it?... maybe an improved tone or bass response... i don't know

Another last thing, about managing the SD-1 bypass problem discused here:

Doing the modifications for the Clay Jones thing would diminished the SD1 bleed problem?

I think it won't do, but have no solid explanation for it... it's more intuition than anything else...

Could i try safely that idea of the FET (https://www.freestompboxes.org/download/ ... d=4864&t=1) to improve the bypass on Clay Jones Mod? Would they be compatible mods?

Thank you in advance, and, please, be kind to excuse my english

Salud

Silvestre · Post by **Silvestre** » 14 Oct 2010, 08:45

Silvestre wrote:To my limited point of view, they (TS808 and Jones' Mod) are nearly the same with a softer clipping section, isn't it?... maybe an improved tone or bass response... i don't know

Maybe the input buffer remains like the SD1 in Jones' Mod

Here (https://img826.imageshack.us/img826/604 ... nesmod.jpg) i drew a color square around the pieces that i noticed that where not the same in SD1 and in TS808... blue is a change in components values, green is an added capacitor, and red is for removed components

Now i have added a yellow spot to show which components does the Clay Jones Mod seems to affect...

It still don't offer too much information on the question of whether it would sound similar to a TS808 or it would be still a SD1 sounding thing...

Maybe things are wrong from the start and there's no such a significative difference, i mean between SD1 and TS808

Silvestre · Post by **Silvestre** » 18 Oct 2010, 08:23

There was something already said about this:

Silvestre wrote:To my limited point of view, they (TS808 and Jones' Mod) are nearly the same with a softer clipping section, isn't it?... maybe an improved tone or bass response... i don't know

It's here [https://www.freestompboxes.org/viewtopic ... 842#p81876], and is something like what i proposed:

tjmicsak wrote:But I thought that the CJOD was pretty much a "clone" of the LOD, which in turn was a TS with better parts and the clipper mod.
The rest of the circuit looks almost identical

i hope I'll pick up more arguments anywhere in the forum... sorry for taking of something old... i only was trying to learn a bit

Silvestre · Post by **Silvestre** » 28 Oct 2010, 10:27

Silvestre wrote: Here (https://img826.imageshack.us/img826/604 ... nesmod.jpg) i drew a color square around the pieces that i noticed that where not the same in SD1 and in TS808... blue is a change in components values, green is an added capacitor, and red is for removed components

Please, don't try this... it keeps on refusing to work in my SD1

WhiteKeyHole · Post by **WhiteKeyHole** » 28 Oct 2010, 15:52

Silvestre wrote:
Silvestre wrote: Here (https://img826.imageshack.us/img826/604 ... nesmod.jpg) i drew a color square around the pieces that i noticed that where not the same in SD1 and in TS808... blue is a change in components values, green is an added capacitor, and red is for removed components
Please, don't try this... it keeps on refusing to work in my SD1

You cannot remove R4 completely, change its value to 10K (if you must). Do not remove R5, change its value... D6 should be replaced with a jumper.

whiskeytown · Post by **whiskeytown** » 30 Oct 2010, 20:07

i try SD-1 to TS808 mod, and really think that some values are to much for example changing C4 from 18nF to 220 nF gives to much mud to overall sound, pedal sounds so much darker, tone control responds only from 2 to 5 o clock, I believe its so much darker than any tube screamer, also changing some resistor values ruins natural attack of drive, make it sounds realy slacky and thin

Silvestre · Post by **Silvestre** » 01 Nov 2010, 08:28

WhiteKeyHole wrote:
Silvestre wrote:
Silvestre wrote: Here (https://img826.imageshack.us/img826/604 ... nesmod.jpg) i drew a color square around the pieces that i noticed that where not the same in SD1 and in TS808... blue is a change in components values, green is an added capacitor, and red is for removed components
Please, don't try this... it keeps on refusing to work in my SD1

You cannot remove R4 completely, change its value to 10K (if you must). Do not remove R5, change its value... D6 should be replaced with a jumper.

Hello, WhiteKeyHole,

Absolutely right... thank you so much... i had a jumper on each component removed place, but wasn't until i returned to the TS808 schematics that i realized the traces couldn't be just the same...

I ended doing a Clay Jones OD Mod that seems to sound better (some asked friends of mine, and my own humble opinions) than the Boss SD-1 directly from the box, testing the two pedals together (one new, and one after the mod... not necesary to have them both ON

)

TDR1138 · Post by **TDR1138** » 27 Sep 2011, 03:41

analogguru wrote:Don´t forget to change the tone-control. Since I don´t have the time to draw that up, here are the steps for the (non-mojo) basic Jones-mod:

1.) Remove R5 - R9, C2 - C6, D4 - D6, IC 1
2.) place a jumper wire instead of D5
3.) assemble a socket for IC1
4.) assemble R5 = 10k, R6 = 1k, R7 = 1k, R8 = 220 Ohm, R9 = 1k
5.) assemble C2 = 100n, C3 = 220n, C4 = 220n, C5 = 220n, C6 stays empty
6.) solder a 10k resistor in parallel to C4
7.) assemble the 2 red 5mm LED´s in D4 and D6
8.) take a chip of your choice (OPA2134) and plug it into the socket.

Now you have a (non-mojo) Jones-SD-1 and saved more than $1.450,--...

analogguru

Bit of a noob question here... So I did all of this over the weekend, minus the opamp change, and I left D5 and D6 stock (based on what I had available). It sounds great, so thanks for the mods, but I have a couple of questions:
1) The pedal has a lot of boost now - unity volume happens with the volume and gain both in the vicinity of 9 o'clock. Is this normal?
2) How can I fix this?

Thanks!

TDR1138 · Post by **TDR1138** » 17 Oct 2011, 17:29

Anyone?