Question about MCI power supply capacitors

[Brian Roth]

Beware of caps sourced from a dicey source,,,,

Bri

 

[Khron]

Yeah, there's only a mere handful of electrolytic manufacturers that i trust (all Japanese - coincidence or not, you decide): Panasonic, Nichicon, United Chemi-Con, Elna and Rubycon.

 

[Rob Flinn]

I am still going through my 636 and it is physically missing a few TI SN7474N op amps. Mouser says they are discontinued. Do any of you know a good replacement for them?

They are not op amps, they are logic chips. Dual D type flip flops to be precise. You probably don't need the "SN" type since they proabably don't operate at speed where timing is a consideration. Therefore there are plenty of non obsolete devices that you could use.

 

[Brian Roth]

IIRC, the SN prefix was TI's own choice. Other brands had a different or no letter prefix.

Nri

 

[Kelvin Zero]

Brian,

I am trying too find some axial, nonpolarized 47uf 16v, 100uf 16v and 220uf 16v caps for my 636 and am having a problem finding them. I usually use Mouser and Digikey. any ideas where to look for them?

Mick

I've been keeping an eye out for these for my console.
I avoid chinese sellers now after several disasters with counterfet parts.
I've just stumbled upon these. The voltage ratings are higher, but is there any reason these wouldn't work?
Jaycar

 

[Khron]

Brian,

I am trying too find some axial, nonpolarized 47uf 16v, 100uf 16v and 220uf 16v caps for my 636 and am having a problem finding them. I usually use Mouser and Digikey. any ideas where to look for them?

Mick

https://www.mouser.com/c/passive-co...ic-capacitors|~Voltage Rating DC&sort=pricing
47-68-82-100-120-150-180-220uF axials in 16-50V ratings, and what's also in stock - pick your favourites, whichever physically fit

Plenty to choose from, as i see it

 

[Kelvin Zero]

https://www.mouser.com/c/passive-co...ic-capacitors|~Voltage Rating DC&sort=pricing
47-68-82-100-120-150-180-220uF axials in 16-50V ratings, and what's also in stock - pick your favourites, whichever physically fit

Plenty to choose from, as i see it

are they bi polar or non polar?

 

[Khron]

are they bi polar or non polar?

Ah, that detail i managed to miss...

Only one matching that description that Mouser have in stock is this:

https://www.mouser.com/ProductDetail/CDE-Illinois-Capacitor/107BPA016M?qs=3tP%2BN51vMXcmVaYjLpsFVA==
But, if need be, non-polar electrolytics can easily be substituted with a pair of double-value back-to-back series polarized electrolytics. It's actually more practical to use normal radial-package ones, which opens up waaaaaaaaay more options, and cheaper, too!

 

[Kelvin Zero]

Ahh thanks.
and I guess certainly cheaper than the ones I linked to

 

[Khron]

double-value back-to-back series polarized electrolytics

https://www.eevblog.com/forum/begin...rse-series-instead-of-a-single-polarised-cap/

 

[porkyc]

Non-polarised capacitors.
Having dealt with a lot of MCI consoles, non-polar caps was a fad.
Just use 100/220/470uF 25v axial/radial as appropriate., which means do not put spread leg radials where there were axials.
PC

 

[MM1100]

Hi - used Nichicon Muse non-polar for the entire console + wima for all the EQ’s so that every channel is now matched + master bus 990 mod + recap power supply. It took a while (I used a desoldering station to be careful with delicate traces) but now everything is sounding great and all my reliability and lack of low end issues with channels has gone away as a result. I am up to 9 John Hardy mic preamps (goal is 16) and use those for tracking.

 

[Kelvin Zero]

wow, that's a lot of work.
Looks great. Where did you find info on those mods?

 

[MM1100]

Crazy but I bought my MCI JH-600 series that had been well used and aged already in 2004. So in the twenty years I have owned it, I have well spent the time in maintenance and mods and its running like new (maybe better than new) now. Same with the Ampex MM1100 16 track I use also well maintained. Solid stuff:

• Mark Richardson for the mix bus mod - amazing http://www.alchematic.com
• Steve Sadler (no longer with us) and Randy Blevins on the power supply maintenance MCI gurus Blevins Audio - analog recording equipment specialist
• Jim Williams on the EQ recomended mods on forums Audio Upgrades
• Sparkos Labs - opamp upgrades that will fit in small spaces Discrete Op Amps
• John Hardy - drop in replacement preamps http://www.johnhardyco.com/pdf/MPC600.pdf only $325 each new
• Doug Williams @emrr - on the bypass cap mods - major forum contributor || ELECTROMAGNETIC RADIATION RECORDERS ||
• @Brian Roth - for general history and maintenance info - thanks!

Very kind sharing of knowledge from too many people to mention - let me know how I can help

 

[MM1100]

In memory of Steve

 

[Kelvin Zero]

Thanks MM1100, that's some great info to look through.
My JH600 is my favourite moneypit