KLH Forty-One Reel to Reel Tape Deck

[stereoguy70]

Has anyone ever had any success in getting the electronics working correctly in one of these decks?

I've owned two of them....sold the first one off in frustration, still have the second one. I recapped the entire thing (second one) and even went so far as to replace all the transistors in it. It worked for a brief while, but now the vu meters have stopped functioning (and yes, I've confirmed it's not the meters themselves, as they work when you put a multimeter to them), the left channel now produces white noise, and the record function refuses to work no matter what. I used same values as the original as much as possible on all the electrolytics, went with Nichicon brand (I've had good luck with them in the past) and used modern equivalent transistors throughout. I know the stories of these being notoriously unreliable, but this is ridiculous.

Why do people like Nakamichi again??

 

[Jonny Ramone]

Never saw one before. So Nakamichi made it? I'd move on, or get a good working deck to use while this drives you crazy.

 

[stereoguy70]

Never saw one before. So Nakamichi made it? I'd move on, or get a good working deck to use while this drives you crazy.

Oh, I have a working (fully restored) Viking Stereo 88 deck that I use regularly. I was just rather hoping to get this one working again rather than it just being a piece of "eye candy".

 

[Jonny Ramone]

I'm kinda looking for a Viking myself, but I have too many decks as it is, and a very sweet, free, Pioneer monster, with worn heads is coming my way soon. I have a Sony TC-366 that I gave up on, as it became a frustrating money pit. It also was 1 motor, with idlers, and an appetite for belts. I don't think I know anybody on this site, or Tapeheads, that has a KLH. I've heard Nakamichi made a few reel decks, but hadn't actually seen one.

 

[stereoguy70]

Yes, Nakamichi made this one and the KLH Model Forty, which was slightly earlier than the Forty-One. Both ended up being notoriously unreliable and was KLH's first major failure. I think Henry Kloss himself was involved with the project before leaving KLH and starting Advent. I think getting Nakamichi involved was his doing. Matter of fact, the first Advent cassette deck, the model 200, was a Nakamichi as well. It also was plagued with reliability issues. This is why Advent introduced the 201 with the Wollensak transport. That was built like a tank! I still use one to this day. You'd think that Henry would have learned his lesson after the KLH reel to reel disaster and avoided Nakamichi for his first cassette deck.......

BTW, the circuit boards on this Forty-One are silk screened Nakamichi Engineering......so this confirms the fact it was produced by Nak for KLH.

 

[stereoguy70]

Still waiting to hear from someone who has actually successfully made one of these fully functioning electronically. The transport works great, no issues there. Am I completely wasting my time by beating this dead horse? LOL!

 

[Jonny Ramone]

Probably. I don't know anybody who has a Nakamichi reel to reel , either. What few were built, must be in the landfill. How stubborn are you? That will determine your course.

 

[revox-b77]

Stick it out...Might be the only one left.

 

[stereoguy70]

Stick it out...Might be the only one left.

 

[audiojones]

Can't help you but I've had a number of these nightmares come through here in the past 25-30 years and I've never been able to get a single one of them working again. All of them were in beautiful physical condition with absolutely no signs of wear on them indicating that they died very early on in life, and the transports always work beautifully (same nice cast aluminum transport as the Harman/Kardon TD-2 and TD-3 as well as Lafayette decks and a few others). All of them exhibited amplifier board failures of one kind or another just as you are describing.

Biggest problem with this deck was the very thin and delicate dual trace circuit boards (different traces on top and bottom of boards) necessary because of the Dolby encoding / decoding feature. Had it been an ordinary deck with just a record amp, playback amp and an oscillator board with no Dolby option it would have been a very nice little compact machine. I spoke to a KLH service station manager on another forum and he clearly remembered what a complete and total PITA these decks and the Model Forty decks were. He said there was an entire service bench set up just for them.

I like the plug in circuit modules they used, that's actually kind of nice. It's the Dolby that f'd everything up. Maybe you can trace out the Dolby stuff and bypass that encoding / decoding circuit altogether so that it will operate like a conventional deck (hard to find schematics and service info on them though). If you have an older amplifier with a tape head input you could always re-route the playback head wiring to the output and use it as a nice little playback only machine (I did that for a while with one of them). Good luck!

 

[stereoguy70]

Well, that's not encouraging.........so it's pretty much a decorative item at this point......

 

[audiojones]

Yep, sorry but without a schematic I'd have to agree. If you keep at it and check all of those super delicate circuit traces on both sides of the board maybe you can find a bad one (or ones). A signal injector and tracer will help here too, but unfortunately there's a lot to go through because of all the Dolby stuff. If you've got the schematic then it may be possible to bypass all that though.

 

[stereoguy70]

I do have the factory service manual with schematic.....been studying that for quite some time. I'll take another look at the traces. If I find nothing, then back ont he shelf it goes.

 

[stereoguy70]

Well, after trying to list it on that auction site as-is for a couple of weeks with no takers, I've decided to give it the old college try again. I suspect my issues are on the main board and it's transistors (which I already replaced) and possibly with the record switches. Once I get it apart again, I'll start checking traces, etc. It sure would be nice to have one of these that actually worked longer than 24 hours! LOL!

 

[Todd E]

I also have a KLH Forty-One I inherited from my uncle. I have yet to try repairing it. It seems like it want's to work, but when I switch to play or rewind from stop or pause, it goes a few seconds then powers down. There is a working one on youtube:

 

[stereoguy70]

I also have a KLH Forty-One I inherited from my uncle. I have yet to try repairing it. It seems like it want's to work, but when I switch to play or rewind from stop or pause, it goes a few seconds then powers down. There is a working one on youtube:

I bet yours needs new belts or a new motor-run capacitor, or possibly both. Mine used to play (its having amp issues currently) but I never could get record to work properly. Notice that the one on Youtube doesn't demonstrate any recording.

 

[Todd E]

I actually just cleaned the old lube out and re-oiled it, a little contact cleaner, and got it running. The shut off problem was actually a kill switch I think, that would trigger because there was no tape running through it. Works pretty good now. I don't now about recording. The counter does not work.

 

[stereoguy70]

Well....I'm at this one again.......found a bad transistor on one of the dolby boards, so I'm going to replace all of those same types on each of the dolby boards (4 on each board), and I also found a bad trace on the main board by one of the meter circuit transistors. I'll be repairing that trace and replacing the transistor at that trace as it also has an issue (same type as the failed ones on the dolby boards). Hopefully after these repairs it will be working as KLH originally intended it to......after that, if I get it working, I'll make a final decision as to keep or sell.......

 

[audiojones]

Good man, you have far more patience than I! What transistor numbers did they use? Makes me wonder if they're commonly known troublemakers or possibly undersized for the job at hand. That would be a great scat to upload onto the AK database as it's hard to find out in the wild.

 

[stereoguy70]

Good man, you have far more patience than I! What transistor numbers did they use? Makes me wonder if they're commonly known troublemakers or possibly undersized for the job at hand. That would be a great scat to upload onto the AK database as it's hard to find out in the wild.

Seems that the transistors that have the issues in this are 2SA458. Replacing them with a suitable substitute.