Chris Robinson Posted October 19, 2002 Share Posted October 19, 2002 I've had my new Music Hall MMF-7 in house for two weeks but due to an overdue vacation taken, the kids' schedules, et al., I just this morning got around to setting it up and plugging it in. The previous owner had warned me that the phono section was "intermittant, maybe due to a cold solder joint" ... but it really didn't matter to me since I was going to use my CDP as my main input. Well, since I've obviously jumped into vinyl now, I thought I'd give the ole Eico a chance before moving up to SET and pre-amp with a phono section. I hooked up the interconnects, booted up the Eico, flipped the selector over to "Phono", and immediately heard a hum from the right channel ... and went over to the left channel which was quiet as a church mouse. Any suggestions (other than pitching it and buying a Scott ) ?? Quote Link to comment Share on other sites More sharing options...
JCturboT Posted October 19, 2002 Share Posted October 19, 2002 Chris, If you wanna borrow my Scott LK-48 to test out its phono section you are more than welcome.You could do that A/B with your Eico at the same time. Jeff Quote Link to comment Share on other sites More sharing options...
NOSValves Posted October 19, 2002 Share Posted October 19, 2002 Chris, I just got done recapping and generally over hauling my HF-81 and the phono section is a pretty conjested area on these amps. Its different in many ways from Scotts. It has 2 small value Axial lead Electrolytic caps (1-10mfd @ 8VDC and 1-25mfd @ 8VDC) also it has 1 .25 MFD coupling cap and 1 .025 ceramic disc it also it incorparates about 6 resistors. It could be any of these causing your problems. Have you actually tried to pass a signal thru it yet ?? I bet the hum is one of the Electrolytics or could even be a tube as far as that goes. Do you have any expereince with soldering at all ? If you do I can tell you what parts to get and walk you thru replacing them. If not your going to have to have someone do the work for you. If you can't find anyone I'll be more than happy to help you out. While were at it you should rebuild the entire unit as I think you said its still all original. Let me know if I can help Craig Quote Link to comment Share on other sites More sharing options...
Chris Robinson Posted October 19, 2002 Author Share Posted October 19, 2002 Jeff, thanks for the offer ... sure, I'd love to give that a spin ... Give me a buzz when you have a moment in your busy schedule. Craig, many thanks as well. I've used a solder iron but am certainly not the wiz you are. I have NOT tested a signal through there because I thought the section was bad, but I'll do that and see what happens. I had a feeling that some caps would need to be replaced. The "balance" on the unit is off, I think ... probably due to aging gangs of resistors. Is there a way to bypass the balance control altogether? I know Mobile had expressed a desire to do that since these old vintage amps seem to trend that way. All help is welcomed. I'm a dope, but not from Hope Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted October 19, 2002 Share Posted October 19, 2002 Sorry to see the phono section not working! That is the one thing I have noticed about many EICOS. Since the phono is a bit tight, I think more than a few of the kit builders end up fudging something there. As Craig said, it is hard to get around, even with the panels off. And when people get these EICOS years later, they only use the LINE inputs for digital and other sources and dont put anything into the phono stages. I think they have nice phono stages, but a lot are subpar as I have noted in the past. Pat said he got his phono stage working GREAT and really liked it. Perhaps he will chime in. I know that I would put some nice stuff in there if redoing it. Perhaps some Dale resistors along with some nice caps. At the least, find the problem, which could be anything from a resister gone, to a bad cap, to a bad solder joint which is very possible. RE-install the tubes and make sure they are GOOD tubes. Clean the sockets as always. Clean the RCAs and the pots that switch to TT. To be honest, I have one unit with a pretty good stage and the other with a so-so stage. I actually end up using my Cary phono in with the EICO when running the TT in he bad one. Works great. Tim Babb just bought a great Wright Sound phono stage on Audiogon for a good price. You should be able to get the phono stage up and running with some help. My second unit, the one that doesnt quite sound as good, is the one with the better phono stage. It does sound very nice and atmospheric but does not beat my Cary unit with MIT caps and holco resistors. Still, it is better than a host of other phono stages and worth getting going. kh ps- What was your total TT price with shipping and how was Underwoodwally to deal with? I think others might be interested. Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted October 20, 2002 Share Posted October 20, 2002 To clarify something here, I just looked at Chris' shot of his EICO HF-81 wiring... He actually has a complete RE-CAP of the entire unit with SPRAGUE ATOMS in the PS position and Orange Drops in all the coupling postitions, even the phono stage. I cant quite tell if they are the 715p or 716p in the coupling positions(the 716p are better with copper leads). IT is probably a cold joint or some resister deal in his phono (this after checking the tubes, cleaning sockets, making sure the switch wiring/pot is ok). I had completely forgotten that he had the total recap. kh Quote Link to comment Share on other sites More sharing options...
Chris Robinson Posted October 20, 2002 Author Share Posted October 20, 2002 Well I ran a signal through it ... and one channel is definitely quiet and the other ... I can hear intermittent music through but the signal is definitely muted. The phono plugs seem to be in tough shape. I'll pull the bottom off and take a look to see if there are any broken connections, crummy joints, etc., as well as test the tubes again for problems. Which tubes are part of the phono circuit? It's not clear looking at the schematics. Quote Link to comment Share on other sites More sharing options...
Tom Mobley Posted October 20, 2002 Share Posted October 20, 2002 They are the two AX-7's on the left, looking down from the top. Make sure they are AX-7's, when I got my Eico it had a phono AX-7 and one of the AU-7's reversed. Didn't work so hot. They look a lot alike so it's easy to make this mistake. Tom Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted October 20, 2002 Share Posted October 20, 2002 Chris, you are running the new table into it right? The phono inputs are in a strange place down in the middle of the RCA jack on the bottom. The wiring could be funky in a number of places. Do you have any extra 12AX7 you can use? Take the tubes out and reinsert. Go to my page to see what is what (link at bottom). Did you ever clean the sockets/switches? Get some Radio Shack Contact Cleaner for $8. While it might not be that, it sure is great to have this stuff around (deoxit is a bit harder to locate unless ordering online). kh Quote Link to comment Share on other sites More sharing options...
NOSValves Posted October 20, 2002 Share Posted October 20, 2002 Chris, Also take the bottom cover off and just visually check that all the resistors and other components hooked to the 2 AX7's for the phono section haven't been moved and touching something they shouldn't. Also do as mobile say's and make extra sure you hook the RCA's to the center 2 out of the 3 Phono,tape connections that is if its wired right. Check the connections there and see if anything has been moved on the inside and touching ground or another component. I have my EICO singing like a bird. The Phono section is indeed nice. Only bested by my 299's phono section so far and much better than a 222C or jeff's LK-48 which is a 222C kit. I installed double value Spraugue Atom caps on my Phono section (mostly because its all I had on hand) but it seemed to quiet the unit it down big time. I tested and all the Lyctics on the phono section and they were all bad on mine and it still worked LOL !! Goes to show you these unit can work with things really messed up ! It will be interesting when I install metal film resistors throughout the EICO like my 299 it may than be a tie between the 2 phono section wise. I believe there is something semi special about the EICO output transformer(mine are the non lipped version I have lipped to switch out) that is good and bad. It sounds every bit as good as my 299 at lower volume but when pushing it above 10 watts output it just can't hang with the 299 period no comparison at all. I had my Daughter confirm this for me just to make sure it wasn't me being bias. This is only with a CD or tuner input though with a LP the EICO never exceeds 10 watts output and never misses a beat !! But the 299 still has a brute force advantage with the phono section and its quiter. Now before I start getting hammered here let me explain why I mention this. The HF-81 seems to sound almost Identical to my 299 at up to about 8 watts of output and may very well have better blackness and sound field (ever so slight if at all). But at over 8 watts the 299 literally walks away with the show my 299 has the same clarity and quality of sound from 1 watt to about 15 and I mean exactly the same. I myself believe this is attributed to better overall quality of the Output Iron. But this is just my guess. This is almost the only component difference resistor and cap wise they are the same manufacturer/type wise. Not sure if the 5AR4 could have anything to do with it ?? Now lets not turn this into a pissing match please !!!! I LIKE THE HF-81 and its second on my list as the intergrated amp to have at this point. I like it better than the 222C because it has a better phono section !! Peace please Craig Quote Link to comment Share on other sites More sharing options...
Chris Robinson Posted October 20, 2002 Author Share Posted October 20, 2002 Thanks for the comments guys ... I'll check it all out and come back a little later. Where would I be without ya? Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted October 20, 2002 Share Posted October 20, 2002 I dont know if I would put all metal film resistors in there unless its something like Dales which are sweeter sounding. I think a lot of metal films can sound crappy and a bit hard. All resistors are not created equal here. I have no doubt that the Scott will play louder than the EICO. None. On the other hand, the subtle differences between units are somewhat hard to hear unless these points are addressed: 1. Great source 2. Properly set up listening room with placement, wiring, details etc attended to The differences in amps besides volume and loudness can be very important, yet all but lost in a typical system setup. When you rreally optimize the sources, layout, placement, and all the little things, then the amp that revreals these cues starts to stand out. THIS is where I think the EICO is very special in that is does things like VERY expensive amps and separates achieve. I had a great shop in Philly that sold ALL VINTAGE tube gear USED. They also had an assortment of CJ, Cary, Audio Research, and the largest selection of Quicksilver used amps I have seen. This simple setup I had in PA (at my then girlfriend's abode) with monitor speakers optimally setup REALLY gave you an idea of the differencing in soundstaging, imaging, tone, etc. And I think amps REALLY start to reveal all the various differences. Also, it really helps if you have been listening to systems like this for years and years as your ears start to really get tuned into these changes. My current system is FAR more revealing and tweaked to a higher level than the above. I just wish my room as this big. Of course, the music is what really matters. And to enter this type of mindset during all listening is absurd really, and missing the point. But it pays to have a very good microscope/area to reveal this. I am just really happy you got your unit going again from that mess you received. You deserve some applause there - I SAW THE PICS! I am also looking forward to getting your new table; I think you will REALLY be happy here. btw, I also hope you get a really nice digital rig sometime, used even. I think the line stage of the EICO is REALLY nice... Plug my Cary Phono into my better unit brings some seriously nice results (the phono on that piece is subpar..needs tweaking). Quote Link to comment Share on other sites More sharing options...
NOSValves Posted October 20, 2002 Share Posted October 20, 2002 Mobile, Yea overall I'm very impressed with the sound achieve from a Amp that only went for $99 factory wired and $69 in a kit !! Simply amazing !! You were definitly right on that its a eye opener !! Or should I say Ear opener. By the way Its really not the ability of the Scott to play louder its the ability for it to play Clean at louder volumes and output over the HF-81 that makes me believe the Iron is of better quality. Craig Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted October 20, 2002 Share Posted October 20, 2002 Not sure of the better quality but I will say the 299 has some BIGGER iron. That amp is rated over 5w more or so per channel. I am still wanting to hear a 299; I need to go down and see ole Edster and carry back his spare 299 for a listen. I have been wanting to hear his Khorns and now that I believe he has his new preamp, it might be time for a road trip! Quote Link to comment Share on other sites More sharing options...
Chris Robinson Posted October 20, 2002 Author Share Posted October 20, 2002 Shouldn't have had those two glasses of wine ... just posted under MH's "Eroica" thread. Ibid. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted October 20, 2002 Share Posted October 20, 2002 Mobile, I can't remember if I did all new resistors in Edsters phono section or not ! I hope so I will love to hear what you think of them. If I didn't it means it was before I started changing them out for Vinyl lovers or his unit was pretty quite in its stock form. I can't remember if it was his or Mike lindsay's amp that I started doing that to them on doh. His may even have orange drops in it. I sure hope you go get it ! Craig Quote Link to comment Share on other sites More sharing options...
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