SAE maintenance

[trek2112]

I have a SAE 2200 and a Mark IB that i got off of ebay recently....Aside of changing the caps in the power supply is there anything else that should do to it to keep it running reliability? I would like to keep it as original as possible.

 

[ryuuoh]

Renew the solder, check the wiring, renew the heatsink paste. Check the bias and offset.
At least that's what I would consider important on a keeper.

 

[trek2112]

As far as the solder goes should I touch it up or redo it all? And what is the bias and offset suppose to be at for these two units?

 

[avionic]

The information you seek can be obtained in the service manuals of each piece of equipment. For a very small donation to a "Save a weiner dog" shelter.
Jim will send you copys of the service manuals.
http://www.jims-sae-site.com/02_system.htm
http://www.jims-sae-site.com/sdrc.htm

 

[ryuuoh]

As far as the solder goes should I touch it up or redo it all? And what is the bias and offset suppose to be at for these two units?

Touch up should be good. Here's an overhaul of a 2600:
http://amp8.com/tr-amp/foreign/sae/sae2600.htm

 

[trek2112]

I'll grab the service manuals soon and look into what things need to be done. If I remember right the amp has a lower serial number on it so I have a feeling I'll have a few things to do on it. I am replacing the power supply caps regardless though. I just need to have time to open them up and find out what i need for parts. Would a full re cap be worth while on this?

 

[spack]

Step 1 of my SAE maintance

 

[hamrules]

Step 1 of my SAE maintanceView attachment 2733932

Making new driver boards there?

 

[spack]

Yes, step 2 is predrivers. I’ve started that. I probably won’t do the output board. I’m not sure yet. My poor old 2600 has got some crispy spots so I thought I’d make a project out of it, switching to available devices and foot prints. But keeping all the old board intact. Some time in the past the fan stopped and nobody noticed.

 

[hamrules]

Very nice.

 

[spack]

If I get it all to work, I’ll certainly make boards available. Although I have little idea how to publicize that or what the interest might be. I see this thread is actually ancient. So I’m off to a flawed start in the first place

 

[hamrules]

There’s a guy on FB that has reproduced these boards too.

 

[spack]

Oh, well gee, I should have looked harder! No point in reinventing anything

 

[hamrules]

This is what he had made, looks like he duplicated what was there.

 

[spack]

Nice! Thanks for sending

 

[spack]

I decided to dial my 2600 back, since my use of it has changed over the decades. I strapped the transformer for 220vac, giving me 52volt rails... Increased the current through the zener clamp that generates the rails for the IPS... and re-biased quiescent and output stages for the now +/-52.5vdc rails. So I get 1/4 the amp it used to be. In reality it clips around 150w/8. Distortion analyzer says it's good relative to original spec (minus some power). No need for a fan, so I don't have to listen to that... mine was particularly noisy. And that 1k/750/300//300750/1k predriver resistor tree doesn't run more than warm to the touch (they used to run way hot). I'll see how it goes driving a pair of TAD 2401s. I don't know if I'll leave it that way or not.

 

[Wingrant]

Is there a way to buy these boards? Mine have some burn marks from overheated resistors

 

[hamrules]

Is there a way to buy these boards? Mine have some burn marks from overheated resistors

You need to get into the Facebook Group then contact “magneto” directly and see what he has or can do for you.

 

[Wingrant]

Any idea what the Facebook group name is. I don’t use it very often.

 

[hamrules]

Any idea what the Facebook group name is. I don’t use it very often.

SAE Scientific Audio Electronics Fans & Collectors Group
He’s in Canada & the group is basically wrapped around his repairing SAE gear.
Don’t argue with him either you risk getting tossed.