JBL SA-600 total restoration

[jan_slagman]

Hello JBL-friends,

Is there anybody in this forum who can tell me what type of powertransistors were used in the JBL SA-600 integrated amplifier. The official JBL-schedule only mentions the JBL parts-number. I also would like to know what type of toggleswitches were used. Does anyone of you know how to obtain the colour: Camo solid tube green. I have been searching all over the Netherlands but couldn't find a matching colour.
I had to saw through the shaft of some potentiometers because the former owner glued the knobs to the shaft. Well, that's all in the game when restoring such an item !!!

I would be very pleased to receive some helpful suggestions.

Kind regards,

Jan Slagman
The Netherlands.

[Hoerninger]

Hi,

in fact I can't give a help in detail. Someone in this forum mentioned that it might have been a 2N3055.
Marshall Leach gives on his site http://users.ece.gatech.edu/~mleach/audiothings.html a link to a

technical desription of the JBL SA-600 by Mr. Locanthi,
former vice-president of engineering at James B. Lansing Sound, Inc.

This will give you the idea. In the Leach Amp plans you will see a practical application with parts lists.
___________
Peter

[jan_slagman]

Hello Mr. Hoerninger,

You've been a great help to me. I hope your information can help me to solve the transistor problems. If anyone else knows what type of powertransistors JBL used in the JBL SA-600, please drop me a line.

With kind regards,

Jan Slagman
The Netherlands.

[jan_slagman]

Hello JBL-friends,

Is there anybody in this forum who can tell me what type of powertransistors were used in the JBL SA-600 integrated amplifier. The official JBL-schedule only mentions the JBL parts-number. I also would like to know what type of toggleswitches were used. Does anyone of you know how to obtain the colour: Camo solid tube green. I have been searching all over the Netherlands but couldn't find a matching colour.
I had to saw through the shaft of some potentiometers because the former owner glued the knobs to the shaft. Well, that's all in the game when restoring such an item !!!

I would be very pleased to receive some helpful suggestions.

Kind regards,

Jan Slagman
The Netherlands.

Hello everybody,

Meanwhile it pointed out one of the NPN powertransistors has a failure. I want to replace this transistor. On page 53 of the servicemanual you can read under Driver Circuit Board: Q9 with JBL-partnumber 12536.

I presume one can't order any original parts of this old JBL SA-600 anymore.
I would be very, very pleased if anyone knows an alternative transistor to replace the damaged one.

With kind regards,

Jan Slagman
The Netherlands

[jan_slagman]

Hello everyone,

Today i got some inside information concerning the power-transistors in a JBL SA-600 integrated amplifier..
It is said JBL used the TRANSISTOR, NPN MPS6520 and
TRANSISTOR, MPS6518

With kind regards,

Jan Slagman
The Netherlands

[Hoerninger]

Today i got some inside information concerning the power-transistors in a JBL SA-600 integrated amplifier..
It is said JBL used the TRANSISTOR, NPN MPS6520 and
TRANSISTOR, MPS6518

Please ask again, these are small signal transistors.
____________
Peter

[jan_slagman]

Hello Mr.Hoerninger,

Thanks for your kind information. I will contact my source and ask him for the right transistors once again.

With kind regards,

Jan Slagman
The Netherlands

[doodlebug]

I had the "Energizer" version this amp back in the 70s. They used 2N3055 transistors in the output. I would suspect, however, that if one or more of them are bad, then there's another problem elsewhere in the amp.

The schematic for the SA-600 found in the links via Dr. Leach's web site, however, shows a fully direct-coupled amp. I seem to recall my Energizer used a transformer to couple the final stage (the one with the 2N3055s).

Given the article, I'd suggest you power it up on a variac once you're replaced the parts you think you need. They'll be taken out again unless all the bad parts are replaced together.

Hope that helps.

Cheers,

David

[jan_slagman]

I had the "Energizer" version this amp back in the 70s. They used 2N3055 transistors in the output. I would suspect, however, that if one or more of them are bad, then there's another problem elsewhere in the amp.

The schematic for the SA-600 found in the links via Dr. Leach's web site, however, shows a fully direct-coupled amp. I seem to recall my Energizer used a transformer to couple the final stage (the one with the 2N3055s).

Given the article, I'd suggest you power it up on a variac once you're replaced the parts you think you need. They'll be taken out again unless all the bad parts are replaced together.

Hope that helps.


Cheers,

David

Hi David,

Thanks a lot for your interesting input. Actually i am a bit astonished to learn how little is known about the parts that were used designing the JBL SA-600 amplifier. Ofcourse you can find a JBL schedule with JBL partnumbers, but unfortunately parts can't be obtained from JBL anymore.
You just have to know the specifications of the factory who made these parts wayback in the mid sixties.
When this project has been finished i will report the alterations we made and the alternative parts we used to this forum.
Maybe this information can be of any help to JBL SA-600 maniacs in future.

With kind regards,

Jan Slagman
Veenendaal
The Netherlands.

[jan_slagman]

Hello JBL friends,

About half a year ago i promised i would report the total restoration of my rusty and heavily abused JBL SA-600 integrated amplifier, which i bought for € 55,00 on Dutch Marketplace (kinda Ebay). Have a look at:

http://www.hififorum.nl/index.php?to...2941#msg162941

Anyone who is interested in technical details can drop me a line.

With kind regards,

Jan Slagman
Veenendaal
The Netherlands

[Fangio]

Veery impressive Jan.

This translation worked for me with Firefox.

http://www.google.com/translate?u=ht...&hl=de&ie=UTF8

[jan_slagman]

Hello JBL friends,

About half a year ago i promised i would report the total restoration of my rusty and heavily abused JBL SA-600 integrated amplifier, which i bought for € 55,00 on Dutch Marketplace (kinda Ebay). Have a look at:

http://www.hififorum.nl/index.php?to...2941#msg162941

Anyone who is interested in technical details can drop me a line.

With kind regards,

Jan Slagman
Veenendaal
The Netherlands

Hello JBL friends,

At the beginning of 2007 i noticed much to my astonishment someone offered a JBL SA-600 integrated amplifier on Dutch Ebay and this was the very first time in my life i saw a JBL SA-600 for sale in Holland. Wayback in 1966 we had a small club of Hifi lovers and i had the JBL catalogue with that amplifier laying on my bed side cabinet.
Before going to sleep i used to look at the glossypicture of that “unreachable” dreammachine and I still have that catalogue. The amplifier was offered for € 50,00 on Dutch Ebay and i won it for € 55,00. But when the amplifier had been delivered and unpacked i didn’t know what i faced. Terrible, totally rusted, dusty, missing a volumeknob, two levers of two toggleswitches, the right black part of the front and the uppercover excisting out of two parts had been broken. The former owner told me he had bought the amplifier from someone who used it in his moisty garage for background music when working on his car A good friend of mine who is an electronic engineer warned me a restoration would cost me a massive amount. After tossing and turning a few days i decided to realize the dream of my youth. Another friend of mine, who is a metal expert, made a new knob, two levers for the toggle switches and the black side part, working on it for some ten hours. Five knobs, five levers and one side part had to be anodized again to get the same colour. The enclosure was cleaned and repainted in olive green.
Two power transistors and fourteen small transistors had broke down and every capacitor and every resistor was replaced. I made a pair of massive American walnutpanels myself and i oiled them the way JBL used to do (boiled lineseed mixed with gum terpentine). It took about half a year before every part had been restored and brought back to specifications. Now the amplifier has better specifications then 40 years ago, when leaving the factory in Los Angeles.
Ofcourse one can buy a new amplifier for the amount i spent to restorate the JBL SA-600, but to me the most important thing was to realize a dream i once cherished in my youth.

With kind regards,

Jan Slagman
Veenendaal
The Netherlands

This a free translation of my Dutch article on www.hififorum.nl

[duaneage]

What's interesting about the "t" circuit design is it became a model for chip amps today. The small amount of parts combine with lack of capacitors made it very easy to make on a chip.

Excellent restoration, quite amazing really. Don't worry about how much it costs because it's obvious your not going to sell it ever.

[Mr. Widget]

A true work of love showing incredible attention to detail... absolutely awe inspiring!!! Thank you, thank you!!!

It is rare to see such outstanding work. That is likely the most impressive project I have seen on this forum to date.

Anyone interested in seeing something truly awe inspiring should look over the photos posted here:

http://www.hififorum.nl/index.php?to...2941#msg162941



Congratulations! I am impressed. Absolutely Magnificent!


Widget

[edgewound]

Not only beautiful work....the photo essay really tells an evolution story of the restoration.

What a treat...thanks for sharing...incredible work.