Vintage Tube Amp

Vintage Heathkit SA-2 Integrated Stereo Tube Amplifier EL-84 phono SEE CONDITION There are 92 photos of the item below. — The photos load incrementally below depending on your connection, please allow a few seconds for the photos to appear — I’ve been using this amplifier for a few weeks now and I still consider keeping it (I have to say I like how it sounds). As it is now, there is an idle hum which is not affected by volume level (it is present with volume all the way down and does not get louder as the volume is turned up). You can hear it if no music is playing. I’ve spent a lot of time on this amp, from cleaning to some troubleshooting. When I first got the amp the solder joint on the main ground wire on the power filter cap had come loose (it is the under the chassis and is a long straight wire leading towards the front panel with several components connecting to it along the wire). — I brought the amp up on a variac and started using it. The first thing I noticed was one of the power tubes was starting to red plate on one side. I did some tube position changing and was confused as it seemed to in some cases follow the tube and in other cases stay with the tube position. A friend gave me 3 used Mesa Boogie branded EL84′s, I tried swapping those in and was having the same problem. The red plating didn’t start right away but took minutes to start appearing, the amp was listenable even with the red plating but I noticed the associated channel has distortion as the red plating started. During all of this swapping I was just changing the 2nd stage position of each channel (the two sockets closest to the front). I decided to just put two mesa boogie tubes in the 1st positions of each stage and there was no more red-plating. I presume this has to do with bad tubes (the mesa boogie tubes were in a bag marked as “used” and were most likely in a guitar amp so those aren’t a good choice). If I decide to ultimatly keep this I will replace the power tubes (it came with a quad of Realistic/Lifetime tubes, 3 marked as made in Korea and one in Japan). I would say you would want/need a new set of power tubes — At one point I had convinced myself that the right channel was not as loud (based on the location pointer on each of the nested knobs). Like I had to turn the right channel up a little to center the image, I use this on my desk so I don’t have a large area or large speakers to fully listen to the imaging. Anyway, this could be the tubes I would assume. I don’t hear distortion though. — I believe the hum is related to the power filter capacitor (my friend that does repairs indicated that as the first thing to change out). It would probably be a good idea to replace the coupling caps, you can see under the chassis there is a number of paper cased caps, ideally all of those should be changed. — Another thing that happened was when I cleaned the chassis I bumped a wire loose. It was one of the blue wires coming from the RCA jacks leading to the input selector. It came loose at the selector switch. When it was loose, one of the channels on the AUX input was out (it was the jack closest to the front panel when viewed from the top). I connected it with a test lead to the closest selector solder point and the channel was active again, but I found out that the tuner and AUX would play at the same time, I changed it to another close joint and that fixed the issue. However I just found out that when something is connected to XTAL phono, that input source is heard on both the tuner and aux sources (I can’t remember if it also played on mag phono). So I may have not found the correct solder joint, this comes with the build manual and there are wiring diagrams showing were it should go, so would be easy to go over and check, I just don’t use the XTAL phono (I don’t use either phono but tested both). So since I just use the Aux and Tuner I just ignored this. I did test the mag phono while having sources on the other inputs and it was fine. — I noticed that one of the power tube sockets doesn’t grip the tube pins that solidly (like the tube is easy to move in the socket and easy to lift out, the inside contact points are likely bent apart). It does not introduce any problems but does tend to move around if touched or if the amp is moved around etc. — The amplifier was missing the rectifier tube (5AR4), I happened to have an equivalent JJ GZ34. So an obvious upgrade would be to get a good vintage tube in there. PHYSICAL CONDITION NOTES — Note that the two rear feet are missing/broken off While I was getting this cleaned up I found two rubber feet from another component. What I found later was the cover didn’t leave enough room for the round feet (the cover has a lip that screws into the bottom chasis, that lip is too wide to allow the big round foot to be used). So you will need to find two rear feet that works with the fitting hole layout. I use the amp with the cover off and I just rest the back on the two rubber feet. — NOTE that the cover has some bending, along the back top lip edge there is an area that feels bumpy like the metal was creased and then flattened, I can see there is some indenting in that area on the top grille, also if you look at the inside bottom of the cover, you can see what appears to be a mild crease line, like a little dip in the metal like it had been bent. The front top edge also is not really straight. When I had it on the chasis I couldn’t get the sides to look straight, it looked like they bowed in a little, or where not straight. Anyway, the cover finish look fine, and it is not too far off but it would need some adjusting and straightening to look correct (I didn’t even notice it until I was taking the photos but once noticed it is hard to miss). To me this is pretty minor, but to others this may be a bigger issues — The front panel looks like it has a slight bend on the left end (if you look down the top edge). I took a lot of photos of everything so you can see for yourself. — As you can see in the photos, some of the lettering is worn on the front panel. There are a few scratches on the bottom metal gold brushed trim. There is some rust on one of the output transformers etc. The rest of the cosmetics you can see in the photos. When I got this it was very dusty, I didn’t clean the underside that carefully so you can see there is still dust on the wires it looks like moldy dust but I haven’t noticed odors, although it is possible, but overall there wasn’t signs of moisture exposure or mold. — GENERAL NOTES — I show all of the tubes in the photos below. The 2 12AX7 positions have 5751′s (RCA and Raytheon). None of the tubes are tested. There are two other sets of preamp tubes (6AN8A and 6AU6), I presume these may be related to the phono sections? This amp has a repuation for having really great output transformers (51-29 1036952). I really like how this sounds. I used to be an audioholic for years and have owned a lot of gear, I’m not going to compare it to anything other than to say it sounds pleasing (if I do decide to keep it I will replace the filter cap and get new power tubes, maybe going further with cap replacement, which can only improve the audio but affects the collectible value for some). From I can see it looks like it is all original with the original build intact. I bought this at a radio swap meet. It comes with the original assembly manual (which is great for troubleshooting). It comes with some large fold out diagrams, some of which seem to be plans for speaker cabinets or other mounting projects. — The downside is the hum, if you turn the volume down you can still hear it, so in a quiet enviornment it is clearly noticeable. But for music listening I like it (I just have to either ignore the hum when nothing is playing or turn it off). I’m still leaning towards keeping this. — See photos for condition details. — I don’t have a way to arrange for a local pick-up of this item, I’m sorry for the inconvienence. The item “Vintage Heathkit SA-2 Integrated Stereo Tube Amplifier EL-84 phono SEE CONDITION” is in sale since Sunday, September 15, 2019. This item is in the category “Consumer Electronics\Vintage Electronics\Vintage Audio & Video\Vintage Amplifiers & Tube Amps”. The seller is “ahp-washington” and is located in Everett, Washington. This item can be shipped to United States.