I know this is an old thread, but I'll put a few tidbits of info here as there isn't much help for these units on the net'.
I have a Model 35. After beating the net to death I'm pretty sure the Model 30, and the Model 35 share much of the same boards and circuitry.
The 35 does have a Dual 1214 turntable in lieu of the Garrard changer on the 30.
My 35 cleaned up nicely, but had a completely dead right channel. I replaced a number of very suspect looking (bulged) electrolytic caps as a matter of course.
These units are interesting. They were designed to be serviced. They have a phenolic- or something similar- composite-like molded bottom chassis. A large backplane type circuit board is screwed down to the chassis, then all the various boards sit down and are screwed onto this backplane and connect to it with pins that stick up from the backplane and mate with sockets built into each board. there are a few ‘plug’ type harness connectors as well. It’s all modular, and any board could be removed and swapped out with a new one pretty quickly in a service environment. The boards themselves are large, and easily worked on.
I’ve been away from the stereo repair hobby for a number of years and most of my bench had been put away so I was basically working with just my DMM and soldering station.
The working left channel sounded charming enough that I wanted to get the unit fully functional. I probed all the semiconductors in circuit referencing the good left channel, and comparing the bad right channel. I discovered a totally shorted transistor in the right channel. It was the first transistor the signal sees in the amp board proper- so a driver or pre-driver input transistor. I removed it from the board and confirmed it was totally shorted in every test case.
Problem was, it had NO identifying markings other than what I determined was a KLH ‘house number’ on it. No amount of research uncovered any reference or cross reference to the manufacturer or any kind of specs or substitution.
There is NO free resource for the service manual anywhere. If you find one on the bay, or somewhere it’ll cost you about $30. That was twice what I payed for the unit itself, so I balked at that. I was able to get a gentleman who had a service manual to send me a pic of the amp board parts list. It only listed the offending transistor as ‘PNP silicon transistor’ and offered no identifying info as to manufacturer or specs themselves. KLH was apparently holding that info close to the vest in the early 70’s when silicon transistors were replacing the germanium pieces in these type units.
Well, I’m not a master technician or amplifier engineer so I was kinda stuck. Did I mention all of this was happening about 5-6 years ago? So I had the unit on a table in the back corner of my shop and would stare at it occasionally and do a few more internet searches for info with no luck. I finally said to myself a few days ago I was going to figure it out.
I measured everything I could about the functioning left side transistor in circuit- operating voltages etc. I removed it from circuit and measured the diode drops, junction capacitances etc. I got out a bunch of new transistors that I had in my inventory from previous repairs on many units over the years and compared characteristics best I could, and asked advice from a few guys I trust.
I arrived at KSA992 as one of a few likely candidates. I had some on hand, and it also shared the same pinout as the original unknown transistor- so I ran with it.
I soldered it in- slapped the amp board back into the unit- dragged out my variac and dim bulb tester from storage and rigged it all up. Brought it up to operating voltage slowly and was blessed with two functional channels. The darn thing actually sounds pretty good. So, be it known on the internet, that KSA992 WILL function as a pre-driver substitution for Q3, & Q4 transistors on the amp board PAB-8 on a KLH Model 35. Now, I have not put it on a scope to look for oscillations etc., but the heatsinks are barely making any warmth, the bias set with no issue and the DC offset within specs. The unit seems happy enough- so take this advice as you will. If I have any subsequent issues, I will report back on it.
I am running it on some medium sized Klipsch bookshelf speakers. It is not a powerful unit, but it has a nice vintage, but detailed, sound. It’s very listenable. The FM tuner functions well too.
The Dual TT unit was pretty crudded up with dried out grease etc. but I had cleaned it up pretty good a few years ago when I got the unit.
One thing that made me reply here is I am now having the same issue as the OP- once I select the phono button and use the TT the unit stays ‘on’ even if you turn off the main power switch to the unit. I believe the turntable motor also runs continuously as well until you unplug the unit (or turn off the power stripfeeding it) at which point it seems to reset the function.
I am going to tear it all apart again, and see if I can figure out the mechanism in the turntable that is keeping the power on to the whole unit even with the Power Switch turned ‘off’.
