The DIY 500 thread

[Denyle]

The big DIY thread for anything & everything 500.

I'll start. DIY 990
12

That's all I have to show so far. Currently building MEQ 500 & 525 copies, which will use the 990 amps. Should have something to show next week. More cool stuff in the design stage which I won't talk about.

[Kronos147]

I have a pair of the Eisen DIY pre-amps on order. I have some input and output transformers built to API specs, and some discrete blocks. I have very little DIY experience, but I have read that the Eisen are well documented, and I have some friends that can help if I get stuck.

I am excited!

[Denyle]

Cool. It's addictive (for me anyway). My EE chops aren't up to designing audio gear from the ground up yet. Maybe I'll get there someday. :D I do enjoy the learning process though. My education was in physics so I only flirted with the more practical side of engineering, and from what I hear, even EE's don't always make good audio designers.

Some PCB's getting populated.
13
14

[Denyle]

Here's a prototype discrete 7 transistor preamp, not yet finished.

18

[Denyle]

Added a UTC transformer. Ready for testing.

21

[peterc]

My EQ project is back on track:

http://www.prodigy-pro.com/forum/viewtopic.php?t=25605&start=135

Peter

[Denyle]

Great news, Peter. I'm looking forward to doing a few of those.

[pan60]

My EQ project is back on track:

http://www.prodigy-pro.com/forum/viewtopic.php?t=25605&start=135

Peter

Peter how is the BLACK RUSSIAN coming?
we 500 form slutz need to know!!!!!
:eek:

[Kronos147]

I finally got my Eisen pres together. Well, a friend finished them. When I had them capped and my friend put the resistors in. At first the units squealed something awful when I turned the gain past 12 o'clock. Again my friend took over and configured one like a stock API 512 and bingo. I copied the other one and yes, they sound good!


http://www.kronosrecording.com/SSL-VSI-API1.jpg

http://www.kronosrecording.com/SSL-VSI-API2.jpg

http://www.kronosrecording.com/SSL-VSI-API3.jpg

http://www.kronosrecording.com/SSL-VSI-API5.jpg

At some point I have to do a lettering layout, and have the panels anodized and silk screened.

[pan60]

I finally got my Eisen pres together.
:D congrats!


Well, a friend finished them. When I had them capped and my friend put the resistors in.
got to love our friends!


At first the units squealed something awful when I turned the gain past 12 o'clock.
ouch, i hat that sound


Again my friend took over and configured one like a stock API 512 and bingo. I copied the other one and yes, they sound good!


what did he reconfigure?




At some point I have to do a lettering layout, and have the panels anodized and silk screened.

GEATORDONE.

[Kronos147]

what did he reconfigure?

One cap and one resistor. He looked at the 'temporary' schematic and changed the cap and resistor value to equal the 312/512. If anyone ends up in the same spot I will ask what values were used, though it is right from the API schematic.

[Denyle]

Are you referring to C7, R12 of the DIY500?

Here's the corresponding API parts:

26

[pan60]

thanks Denyle:D

[Denyle]

Pan60, I'm only guessing here. (the cap-resistor in the NFB usually helps w/ oscillation) You might want to verify with Kronos147 if you still have problems.

[Kronos147]

I just checked, I changed C6 and R13. I can only tell you that looking at the circuit card. I think the R13 went to 200 ohms. I think the voltage went up on C6, not sure about the other variables.

Bottom line, I was in way over my head and getting close to bringing it to the repair place in shame. I am not sure I would go for it again with a different kit, but I may do another Eisen now that I can copy mine.

I do want to learn to check it out though in case of problems.

[okgb]

I know some people have made some , but
anyone know the latest sleeper deals
for buying a 10 or 11 space rack new ?

[purpose]

http://www.lazpro.com/units.jpg

[LunchBoxHero]

Purpose... those are cool! are they production units or strictly a DIY limited edition? Can you tell us more?

[purpose]

Purpose... those are cool! are they production units or strictly a DIY limited edition? Can you tell us more?

Hi James,
The ACL (American Compressor Limiter) is a DIY 525, with added attack and balanced input.
The EQA is an eq based on an oldish BBC design, with added high and low pass filters. I'm toying with the idea of releasing it as a kit, but haven't made up my mind.

More details at http://www.lazpro.com/

peter

[pan60]

cool!!!!!:D
i want to dabble in the DIY stuff but i am still to swamped trying to get the for sale gear reviews done.
but soon i hope!

[purpose]

cool!!!!!:D
i want to dabble in the DIY stuff !

Don't do it. It is a bottomless pit.

[pan60]

Don't do it. It is a bottomless pit.

:D:D
that is my fear.
just trying to collect all these pres, is a bottomless pit!:eek:

[purpose]

Here's an optical comp I'm working on.

http://www.lazpro.com/fsc.jpg

[pan60]

cool!!!!!

[Denyle]

Don't do it. It is a bottomless pit.

The bottom goes only as deep as the pocket. :eek: :D

[natek]

The bottom goes only as deep as the pocket. :eek: :D

Deeper sometimes! :D Thats why i have no credit cards, best to control every urge to have that next piece unless it is really affordable! I had to face the fact I am a junky!:rolleyes:

But I am much happier building my own gear than spending enormous amounts of hours working to save money to buy one piece of "pro-sumer" middle of the road neverdoesquietwhatyouwantitto gear!!


Nate

[pan60]

Deeper sometimes! :D Thats why i have no credit cards, best to control every urge to have that next piece unless it is really affordable! I had to face the fact I am a junky!:rolleyes:

Nate

my wife has seazed my Credit Cards

http://img2.mysmiley.net/imgs/smile/confused/confused0059.gif (http://www.mysmiley.net/free-sick-smileys.php)

[natek]

Thats a smart woman! If you do ever delve into DIY it is lots of fun and very fulfilling when you get to use the hand buit gear in a session! Time consuming and at some expense but I cant complain too much! Give it a try on something basic, the 500 series modules like the stuff Peter Cornell of Bizarre Audio (great guy by the way!) or Eisen audio kits are a great way to get yourself into trouble if you already own a lunchbox!:) I see you have reviewed the Bizarre stuff that Peter and Matt have been doing so you already have a good idea!

[Denyle]

Here's a 2 to 1 mixer or wet/dry processor.

32

[LunchBoxHero]

Hi James,
The ACL (American Compressor Limiter) is a DIY 525, with added attack and balanced input.
The EQA is an eq based on an oldish BBC design, with added high and low pass filters. I'm toying with the idea of releasing it as a kit, but haven't made up my mind.

More details at http://www.lazpro.com/

peter

Hi Peter, I noticed on your site, there is a DIY 525 Circuit Board kit (http://www.lazpro.com/buy.htm). Would you like me to add this to the database? and your op-amp to the resources page where I will shortly be creating a DIY section?

[pan60]

I will shortly be creating a DIY section?

very cool!! :D
maybe some of the tech's out their can chime in and offer some help when needed.

[LunchBoxHero]

indeed, I am going to create a little table on the resources page with some DIY info... parts, kits, links to threads on other forums that offer help. And then there is this site (http://aermotorstudio.com/eisen/) that already has some cool BOM info on Eisen kits.

[pan60]

wow cool site!

[purpose]

Hi Peter, I noticed on your site, there is a DIY 525 Circuit Board kit (http://www.lazpro.com/buy.htm). Would you like me to add this to the database? and your op-amp to the resources page where I will shortly be creating a DIY section?

Hi James,
Feel free to add anything you like, but would you be good enough to include the EQA.

Cheers
peter

[Denyle]

Op amp party

1122, KDJ4, DIY990, something I made this morning, some little hybrid thingy. I ripped the 4th from an obscure 60's design (the original Record Plant console).
62

[pan60]

cool!!
:D

[[silent:arts]]

Just wanted to say Hi with some more OpAmps :D

API 2520 (1990), LAZ25 from purpose, DIY 2520, DIY Melcor:
http://www.silentarts.de/DIY/temp/2520_OpAmps.jpg

early Hardy 990, Hardy 990C, MM-990, JFET-992:
http://www.silentarts.de/DIY/temp/99x_OpAmps.jpg

a DIY section would be fine, I just started working on some 500 compatible projects ;)

[pan60]

sweet!!!!!!:D:D

[Denyle]

;420']
a DIY section would be fine, I just started working on some 500 compatible projects ;)

Exciting. Any tubes inside?

[[silent:arts]]

Exciting. Any tubes inside?
no. for tubes I don't like this format and PSU limitations.

Neumann inside will be the first :)
at the moment I'm in contact with Haufe for the original transformers :cool:

[futur2]

;428']
Neumann inside will be the first :)
at the moment I'm in contact with Haufe for the original transformers :cool:

wow very interesting!

[tubemooley]

Kronos147 - Who's potted 990 block are you using in your Eisen's? You wrote SSL-VSI-API on the front panels of those. What does that refer to? And you're already loaded up with like six modules from VSI? Oh man..... yer killing me here. Where do you live so I can come burgle you? (bad joke). DW.

[tubemooley]

I know some people have made some, but anyone know the latest sleeper deals for buying a 10 or 11 space rack new?

Bump this. Reasonably priced racks with a good, quiet power supply are a must. I'm all over this. The commercially available racks are way overpriced. DW.

[Denyle]

The first of these is coming along finally. Just needs a few switches, then I can see how my "mods" perform.

66

67

[pan60]

The first of these is coming along finally. Just needs a few switches, then I can see how my "mods" perform.

70

71

:D:D:D
cool!

[Denyle]

http://www.denyleguitars.com/images/meq500_final_01

[pan60]

looks very sweet!

[Denyle]

Sounds very sweet too.

[Kronos147]

Kronos147 - Who's potted 990 block are you using in your Eisen's?

Those are actually the VSI 'baby blocks" for lack of a formal name. I am working with the VSI guys on R & D.

The Eisens came about because I suspected the VSI guys were over thinking their design. I had hoped to prove to them that their blocks with (basically) off the shelf transformers would be great in a mic pre.

What ended up happening is we took the VSI L-21 design, which has an UI output transformer, and tried it with an EI output transformer. Now that is the L-22 Overtone, and the L-21 is the Spectrum.

The VSI blocks are really really clean and do not really impart a sound. I like that! The UI transformer is clean, articulate, and has an extended range without exaggerating anything. The EI transformer, which is much like the API with some nickel, has more pronounced lower mids and bass.

I wish I could tell you the L-21 Spectrum and L-22 Overtone and the baby block was for sale, but the Engineers are still over thinking things. :rolleyes:

I love those pres to death. I get comments on their sounds all the time.

*Sigh*

[tubemooley]

Very cool. Thanks for the info. Just hearing about those VSI blocks is a lot better than nothing. Hopefully the guys at VSI will decide to start marketing more of their stuff. We'll see. DW.

[gar381]

http://gar381interests.com/AML27_front72.jpg
http://gar381interests.com/MELCORAML27_500SERIES2.jpg
http://gar381interests.com/MELCORAML27_500SERISE3.jpg
http://gar381interests.com/AML27_TEST_SETUP.jpg

GARY

[pan60]

: )~

[bendymusic]

Oooh nice one!!

[gar381]

More DIY modules..

http://gar381interests.com/525_new_knobs.jpg

peter purpose 525 clone with gar2520 DOAs

http://gar381interests.com/312front.jpg

312 clone with cinemag transformers and gar2520 DOA

http://gar381interests.com/VP26_Rack372.jpg

500 series DIY rack with some 553 EQ clones with switchable freqs,
EA2503 transformers and gar2520 DOAs
A pico 500 from the days when Roger was selling PCBs
and one of Classics wonderful VP26 pres with gar2520 DOA

GARY

[[silent:arts]]

Great work !!!

[LunchBoxHero]

More DIY modules..


Wow... beautiful work, thanks for posting!

[pan60]

yes very sweet!

[bendymusic]

total envy.. :D

[peterc]

SSL E series mic pre, first version. The final will have a DI input as well.

First time have heard a Jensen input transformer, sounds really good.....

http://img.photobucket.com/albums/v318/peter_cornell2002/4K%20Mic%20Pre/DSC00753.jpg

http://img.photobucket.com/albums/v318/peter_cornell2002/4K%20Mic%20Pre/DSC00750.jpg

[gar381]

Looks GREAT peter !!

Gary

[pan60]

looks nice!
and it has one of my favorite knobs!
:D:D:D

[parasitk]

My two Eisen EAC312v kits + Red Dot op amps:
http://farm3.static.flickr.com/2771/4387111737_37a87dde01.jpg (http://www.flickr.com/photos/parasitk/4387111737/in/set-72157608345819435/)

Red Dot 2520:
http://farm5.static.flickr.com/4051/4387112647_77bccf2188_m.jpg (http://www.flickr.com/photos/parasitk/4387112647/in/set-72157608345819435/)

Finished this today, although I'm still waiting for some backordered caps:
http://farm5.static.flickr.com/4044/4420236281_19644c9a63.jpg (http://www.flickr.com/photos/parasitk/4420236281/in/set-72157608345819435/)

:o

//Chris

[pan60]

sweet!:D

[parasitk]

Finished my EAC 312v's today!

http://farm5.static.flickr.com/4004/4439267409_33cb29465f.jpg (http://www.flickr.com/photos/parasitk/4439267409/in/set-72157608345819435/)

More: http://www.flickr.com/photos/parasitk/tags/eac312v/

:D:D:D

[bendymusic]

Beautiful!!!!!!!!!!!!!!

[pan60]

Beautiful!!!!!!!!!!!!!!

yes!!!!!:D

[peterc]

New version of the SSL k mic pre with built in DI

Sounds excellent

http://img.photobucket.com/albums/v318/peter_cornell2002/4K%20Mic%20Pre/V44.jpg


http://img.photobucket.com/albums/v318/peter_cornell2002/4K%20Mic%20Pre/V42.jpg

[pan60]

sweet!:D

[gar381]

My newest DIY module:

http://gar381interests.com/SSL9kfrontfrontW72.jpg

http://gar381interests.com/SSL9kbackW72.jpg

http://gar381interests.com/SSL9krackW72.jpg

This guy is an SSL9k Mic Pre clone with a variable hi pass added.
Still missing a few parts that are backordered but I should
have a pair of these guys fired up in a week or so.

PCB was designed by bruno2000 over at the lab
and is for sale here:

http://www.prodigy-pro.com/diy/index.php?topic=10776.0

GARY