Micro250 Rej's Dist+ gone Grey DOD 250 in 1590a

[timbo_93631]

I like it with the Tungsram OA1160's that are in there, but stock 1n4148's are nice too for a crisper sound.  Just subbed the parts to make it a '77-'78 Grey spec DOD 250.  Next up is a Darkside in a 1590bb, I think I am gonna have a bit of the agoraphobia Jon mentioned a few days ago in his Trrr-treeeh build report!

[GrindCustoms]

Really glad to see one of these pcb boxed!

Looks really nice, the match of distressed and hand painting/writting, rocks!

Was'nt it a LF351N in the grey DOD250?

[timbo_93631]

LF351N was in the later yellow versions, LM741 were in the grey ones.  I looked at a bunch of different layouts and schematics as well as gutshots of all the greys I could find for this one th nail down the vaules.  There are alot of discrepancies in the different info out there but I tried to match up with the gutshots using the other stuff as a guide to spotting what was what.  of course with the non-original diodes in there it isn't a true Grey 250!  Really liked working with this little board.

[GrindCustoms]

I agree that doing deep research about a circuit is always really interesting, sorry that i could'nt help you for this one, just did'nt have the time for....

Have you «documented» the difference between the variation of this circuit so they can be built on this pcb layout?

If yes, it would be nice if you could send them my way, i would add them to the BOM/Build DOC of the circuit and give you the credits for that part of the document.

Let me know what you think

Rej

[timbo_93631]

You got it, I'll compile my notes and send them your way this weekend.

[alanp]

I am loving how you use the bulky, traditional parts, not the slimline trendyboy unobtanium (ohgodtheSHIPPING) from Mouser and Smallbear, and still fit pretty big PCB's in there

[GrindCustoms]

You got it, I'll compile my notes and send them your way this weekend.

Awesome, sending you a pm

[Bret608]

Hey, I'm excited to see this too! I've been thinking over what to do with mine. I went in a guitar shop across the way from where I work and saw an old Ross Distortion that happened to have the bottom plate off. I got intrigued as I know it's akin to the D+ and 250. It had an RC4558 IC and what looked to be 1n4148s (it was the black version). I listened to some samples and liked it, so I may indeed try it on this board. I did some research and I think an RC4558, 1n270s, and tantalum for the 1uf caps could get me close to the tan version. Let me know if this sounds incorrect at all.

Anyway, I love that this board can be such a cool template for tweaking. How are you liking the sound?

Cheers,

Bret

[pickdropper]

Very nice build.  Inside and out.

[Scruffie]

Hey, I'm excited to see this too! I've been thinking over what to do with mine. I went in a guitar shop across the way from where I work and saw an old Ross Distortion that happened to have the bottom plate off. I got intrigued as I know it's akin to the D+ and 250. It had an RC4558 IC and what looked to be 1n4148s (it was the black version). I listened to some samples and liked it, so I may indeed try it on this board. I did some research and I think an RC4558, 1n270s, and tantalum for the 1uf caps could get me close to the tan version. Let me know if this sounds incorrect at all.

Anyway, I love that this board can be such a cool template for tweaking. How are you liking the sound?

Cheers,

Bret

Only thing to mention is that the 4558 is a dual opamp while a 741 is single so you can't put them in the same circuit board without modification.

[GrindCustoms]

Hey, I'm excited to see this too! I've been thinking over what to do with mine. I went in a guitar shop across the way from where I work and saw an old Ross Distortion that happened to have the bottom plate off. I got intrigued as I know it's akin to the D+ and 250. It had an RC4558 IC and what looked to be 1n4148s (it was the black version). I listened to some samples and liked it, so I may indeed try it on this board. I did some research and I think an RC4558, 1n270s, and tantalum for the 1uf caps could get me close to the tan version. Let me know if this sounds incorrect at all.

Anyway, I love that this board can be such a cool template for tweaking. How are you liking the sound?

Cheers,

Bret

Only thing to mention is that the 4558 is a dual opamp while a 741 is single so you can't put them in the same circuit board without modification.

+1

That would be an elaborate conversion to perform, some trace cutting and mostly jumpers.....

Use this layout with a single op amp like the LM741 of LF351 with some Ge diodes, and you'll get something really similar to the Ross.

The Ross is quite a compressed distortion that pains to get over unity gain even with all control maxxed, personnaly i would just go with the Ge Diodes and the tant...., you'd be really close to it.

[Bret608]

Ah, that makes perfect sense! Thanks Rej and Scruffie. I did not realize the difference on the op amp. Tants and Ge diodes it is!

[Scruffie]

Hey, I'm excited to see this too! I've been thinking over what to do with mine. I went in a guitar shop across the way from where I work and saw an old Ross Distortion that happened to have the bottom plate off. I got intrigued as I know it's akin to the D+ and 250. It had an RC4558 IC and what looked to be 1n4148s (it was the black version). I listened to some samples and liked it, so I may indeed try it on this board. I did some research and I think an RC4558, 1n270s, and tantalum for the 1uf caps could get me close to the tan version. Let me know if this sounds incorrect at all.

Anyway, I love that this board can be such a cool template for tweaking. How are you liking the sound?

Cheers,

Bret

Only thing to mention is that the 4558 is a dual opamp while a 741 is single so you can't put them in the same circuit board without modification.

+1

That would be an elaborate conversion to perform, some trace cutting and mostly jumpers.....

Use this layout with a single op amp like the LM741 of LF351 with some Ge diodes, and you'll get something really similar to the Ross.

The Ross is quite a compressed distortion that pains to get over unity gain even with all control maxxed, personnaly i would just go with the Ge Diodes and the tant...., you'd be really close to it.

Don't know much about the ROSS but it could be those Ge diodes are the reason for its struggle to reach unity.

If you did use a 4558 you could use the other half to boost the output if this is the case.

[GrindCustoms]

I had a black Ross distortion for a while, it was just above unity but sounded really great.

Still had it when i built this Dist Plus:



And with 2 Ge it's really close. I tried everything that can possibly clip in that thing....