New to DIY

[Almonds]

Hey there!
I’ve been posting here for a year or so and I’ve really got the bug.
I’ve acquired 4 vintage amps in the time and I’ve started building and repairing stuff. I built the bottlehead quickie preamp and I’m in the middle of a repair on a vta st120.

My question is:
What’s a good vintage (preferably 70s, but doesn’t have to be)
SS amp or integrated or pre that I can find on CL or eBay sold as parts only that would be for a beginner to get into to repair?
Or if anyone has something good for this purpose that they would sell to me.
I currently have and enjoy a kenwood ka9100 ka3500 and model 600. If these or something like them is a good starter project let me know.

Thanks everyone! I’m enjoying this journey!

 

[OMGCat!]

I'd say something by one of the brands with it's own forum here as you'll likely to find a good few repair threads that will be very well documented.
Go with stuff that has discreet components so you don't have to try and chase down ICs that may or may not be fake or not built to proper standards.

I'd say something like a smaller Pioneer, Marantz, Kenwood or even an HK330 as there are a bunch of great threads on those.

Don't forget diagnostic and repair tools to go with your repair projects.
I like to have a few different multimeters around like a DMM, VTVM and SS analog meter. A decent DSO can be had for $300 or so depending on the features you want. I've got an old Tek DSO and CRT scope and use them both regularly. A signal generator and frequency counter are super handy as well (or something newer with everything built in). Then you need a bunch of leads and jumpers and clips and whatnot.
For soldering, a good Weller station can be had fairly cheap especially if you go used. I bought a Hakko 472D desoldering station as I hate messing with pumps and wick but you don't have to go that nuts right away. See what works for you and go with that.
Building up your tools is almost as fun as messing around with the projects.

 

[gort69]

The KA-9100 and the Model 600 have well deserved reputations for being a PITA to work on and would not be a good choice to learn on. The KA-3500 is also a PITA due the lack of a removable bottom cover - the guts need to be pretty much completely removed from the chassis to access the solder side of the main board.

If you like Kenwood the KA-5700 and KA-7100 would be good choices - I'm sure there are many others.

 

[Almonds]

thanks for that info gort! That's really good to know. Both the 5700 and 7100 are appealing to me, so I will keep an eye out for cheap broken ones.

 

[Steven Tate]

I happen to be a Marantz addict. Of course, it is only one of many fine manufacturers of SS units in the 70's. I was in your spot about three years ago when I got into the hobby with very little experience. I wanted to refurbish a Marantz 2270 and was given good advice to start with a simpler unit like a 2220. I found one on eBay at a reasonable price and it was definitely easy to work on. And like OMGCat said, there was a large reservoir of experience on the Marantz forum to help me through problems and give advice. And when I finished the 2220, I had a great sounding little receiver. I then worked up to a 2230, 2245, 2270, 2275 and 2325 (I told you I was an addict. lol). But the gist of it is - start simple and you will eventually find yourself taking on the bigger projects. And be sure to read Echowars great thread at the top of the DIY forum: So You Want to Repair Audio Gear, Eh?
Steve

 

[Almonds]

My friend pointed out this piece to me. Does anyone know if this would be a good starter piece?
I'm also going to keep my eyes out for a 2220, thanks steven!

https://www.ebay.com/itm/222955603593?ul_noapp=true

 

[avionic]

Pioneer SA's are pretty easy to work on.

 

[rcs16]

Not the SA-8900 that we had to re-design because the replacement bjts threw the NSA bias network out of wack.

 

[avionic]

Not the SA-8900 that we had to re-design because the replacement bjts threw the NSA bias network out of wack.

There are 60+ SA models to choose from.. So stay away from the 8900 ! Jeesh , tough crowd..
All the SA's I've reworked were pieces of cake.

 

[cwh]

Yeah 70s Pioneers can be more forgiving than other brands. SX-780 is wide open plus you can join @rcs16 and build yourself a pair of STK modules and take it to the next level. http://audiokarma.org/forums/index.php?threads/stk-0050-replacement-for-sx-780-and-others.721181/

 

[avionic]

Yeah 70s Pioneers can be more forgiving than other brands. SX-780 is wide open plus you can join @rcs16 and build yourself a pair of STK modules and take it to the next level. http://audiokarma.org/forums/index.php?threads/stk-0050-replacement-for-sx-780-and-others.721181/

SS amp or integrated or pre that I can find on CL

He didn't mention recievers..

 

[rcs16]

Jeesh , tough crowd..

oops do not mean to step on toes, but just stating SA-8900/9900 NSA amps are not a

good starter project

So as you say chose one of the other 50+ Sa models. I did not realize there were that many of them.
To learn to fix electronics, Pioneer in general, is one of the better ones as far as documentation goes.

He didn't mention recievers..

Yeah stay away from tuners? They do require more test equipment to do them right.

 

[avionic]

Note .. I didn't mention Yamaha. There not as easy to work on for a rookie.

 

[cwh]

He didn't mention recievers

How about a non-NSA SA-6800? Just like the 780, easy in easy out.

 

[avionic]

Those flourascan models are sweet.

 

[Almonds]

Does anyone know about the Luxman L-10? I have an opportunity to get one of those where one channel is out.
I found a service manual online. Any ideas whether this might be a good starter project?

 

[BinaryMike]

Products that were originally sold as kits can make an excellent starting point for DIY newbs, because excellent manuals are available. The Dynaco PAT-4 preamp, Stereo 120 power amp, SCA-80 integrated amp and others can often be had for very small money.

 

[Almonds]

I'm back! I found a Pioneer SA-706 for $35 that the guy said wasn't working at all.

I brought it home and did the prerequisite DE-oxiting and got it working a little bit. Did another round with the DO, and it's much better now.

Actually, the only problem now is that it has a constant buzz that changes when I touch the chassis.

Also, I think the meter lights are out, but that's not a big deal, unless them being burnt out could be causing the buzzing?

I'll go search the forums, but if anyone has any tips on what to check, any help would be greatly appreciated!

Thanks.

 

[Almonds]

Pioneer SA's are pretty easy to work on.

I got my Pioneer SA-706 working!!

Thanks so much for the advice that they were easy to work on.
Also, I love that it has meters and it sounds great!!

I'm also only at 3/10 on the volume dial and it's pretty loud, super clear. Powering some Martin Logan Motion 15s now.

I've just got to order some replacement bulbs for the meters now, and she's ready to be my backyard amp!

If anyone cares, the major problem on this guy was the speaker relay had gone bad. It was causing intermittent sound and a level mismatch. There was also a chewed or corroded ground wire from the rca jack panel.

It appears someone had tried to maybe do a LED retrofit or something. They had mangled the original lamp circuit and drilled into the circuit board and wired in a new circuit with a ceramic resistor (350 ohm)

I pulled all that out and am putting in the original 47 ohm resistor and trying to get some 8v 55mw lamps.