Hello there! My passion for old audio equipment has lead a friend of mine to finish off his junkjard... here's what he gave me today:
Emerson EA-2400H - A little integrated ss amp from the early (?) seventies. It looks like it has seen better times, and also the build level doesn't seem extremely good. With a quick look inside I found some resistors burned in the power amp board, along with some driver transistor substitution (the left ones appear original, BD138/139, but the right ones appear new, still the same type). The output ones are probably new, they're BD711. They are all four equal, so I'm suspecting a quasi-complementary output stage. It does miss the power cord.
R.C.F. AM5040 P.A. Amplifier - This is a mono ss pa amp from '79 I think. It appears well built, with original TIP35 output tr and a replacement TIP36. It has 2 big transformers inside it: the other one I think is an audio output tranny (yes, output) because the amp has many impedance taps, from 4 ohm to 250 ohm. It has a strange little switch inside it saying on one side "p.a." and on the other "h.f.". Don't know what it means, but it was set on "h.f." mode.
Philips FD RB 534 - I think that this little thing is a cable broadcast module, I don't know the proper english word, in italian is filodiffusione. It is little and with a beautiful wood chassis over the plastic bottom. It has a VU meter on the faceplate, an on-off button, and other 7 buttons: they go from 1 to 6, and the last one has an "infinite" simbol over it. It has a DIN input and a strange two-wire plug, reminding of old european mains plugs.
Technics Stereo Cassette Deck 615 - Beautiful old time cassette deck, with one cassette module, dating '77. It is almost mint, very clean inside for it's age. It has a strange reading mechanic: it is not vertical or orizontal, it is angled by 45 degrees. Also with VU meters and self-opening cassette van
This one has the same case styiling of my Technics SL1200 record player, and I don't have a cassette deck in my system. I am intentioned to keep this in my hi-fi.
I didn't test these units. Any thougts about them? If you have experience with them let me know...
(btw this is not a "for sale" thread, I only want your opinion on them).
Keep posting!
Emerson EA-2400H - A little integrated ss amp from the early (?) seventies. It looks like it has seen better times, and also the build level doesn't seem extremely good. With a quick look inside I found some resistors burned in the power amp board, along with some driver transistor substitution (the left ones appear original, BD138/139, but the right ones appear new, still the same type). The output ones are probably new, they're BD711. They are all four equal, so I'm suspecting a quasi-complementary output stage. It does miss the power cord.
R.C.F. AM5040 P.A. Amplifier - This is a mono ss pa amp from '79 I think. It appears well built, with original TIP35 output tr and a replacement TIP36. It has 2 big transformers inside it: the other one I think is an audio output tranny (yes, output) because the amp has many impedance taps, from 4 ohm to 250 ohm. It has a strange little switch inside it saying on one side "p.a." and on the other "h.f.". Don't know what it means, but it was set on "h.f." mode.
Philips FD RB 534 - I think that this little thing is a cable broadcast module, I don't know the proper english word, in italian is filodiffusione. It is little and with a beautiful wood chassis over the plastic bottom. It has a VU meter on the faceplate, an on-off button, and other 7 buttons: they go from 1 to 6, and the last one has an "infinite" simbol over it. It has a DIN input and a strange two-wire plug, reminding of old european mains plugs.
Technics Stereo Cassette Deck 615 - Beautiful old time cassette deck, with one cassette module, dating '77. It is almost mint, very clean inside for it's age. It has a strange reading mechanic: it is not vertical or orizontal, it is angled by 45 degrees. Also with VU meters and self-opening cassette van
This one has the same case styiling of my Technics SL1200 record player, and I don't have a cassette deck in my system. I am intentioned to keep this in my hi-fi.
I didn't test these units. Any thougts about them? If you have experience with them let me know...
(btw this is not a "for sale" thread, I only want your opinion on them).
Keep posting!
Yeah! In fact it seems sturdy... and it is quite mint for it's age. I was planning on replace the filter caps with new hi-grade types, and put blue tac nearly everywhere... any suggestion on reducing motor noise (either sound and electrical/EMF/RF/something) like caps in series... I'm not an expert in tape decks, what are the mods I should do to bring it in a audiophile-grade status?
And other thoughts about the rest?
And other thoughts about the rest?
Hi Giaime,
Neat pile 'o stuff. You can sharpen your troubleshooting skills, just for fun.
The cassette deck has a weak spot called rubber. Another called felt clutches (can be repaired) and another called a capstan bearing. If the motor is noisy, the brushes and / or bearings may be shot. Replace the motor. The capstan bearing is generally not repairable. When worn it will draw the tape in towards the mechanism. If the highs come in, go out and come back in when you play a cassette, the capstan bearing is shot (or well down the road). Soon the edge of the tape will get damaged against the head guide.
Blue tack is absolutely no help in a cassette machine. It may make you feel better and that's about it.
-Chris
Neat pile 'o stuff. You can sharpen your troubleshooting skills, just for fun.
The cassette deck has a weak spot called rubber. Another called felt clutches (can be repaired) and another called a capstan bearing. If the motor is noisy, the brushes and / or bearings may be shot. Replace the motor. The capstan bearing is generally not repairable. When worn it will draw the tape in towards the mechanism. If the highs come in, go out and come back in when you play a cassette, the capstan bearing is shot (or well down the road). Soon the edge of the tape will get damaged against the head guide.
Blue tack is absolutely no help in a cassette machine. It may make you feel better and that's about it.
-Chris
Thanks Chris! I'm glad I found you here...
I haven't powered it up, yet, as I plan on a complete cleanup when I've got time. My friend says that it has never (or almost) been used, so the capstan should be good. With rubber, you mean the rubber chain that transfers the rotation from the motor to the cassette? It worns out with age? Do I have to change it (maybe I can salvage something out an old VCR...)
I haven't powered it up, yet, as I plan on a complete cleanup when I've got time. My friend says that it has never (or almost) been used, so the capstan should be good. With rubber, you mean the rubber chain that transfers the rotation from the motor to the cassette? It worns out with age? Do I have to change it (maybe I can salvage something out an old VCR...)
Hi Giaime,
The rubber meaning the capstan belt, idler wheel(s) and pinch roller. If the belt tension is good just give it a light wipe with methol hydrate.
The capstan shaft and bearing can be checked by rocking it gently back and forth 90 ° from the pinch roller contact direction and then from the direction of pinch roller contact. You need to do this without the rear flywheel support in place.
Clean with methol hydrate and relubricate with a light single weight oil with no additives. Not too much! Clean the end of the capstan shaft after it's reinstalled. Clean the heads with methol while you are at it.
-Chris
The rubber meaning the capstan belt, idler wheel(s) and pinch roller. If the belt tension is good just give it a light wipe with methol hydrate.
The capstan shaft and bearing can be checked by rocking it gently back and forth 90 ° from the pinch roller contact direction and then from the direction of pinch roller contact. You need to do this without the rear flywheel support in place.
Clean with methol hydrate and relubricate with a light single weight oil with no additives. Not too much! Clean the end of the capstan shaft after it's reinstalled. Clean the heads with methol while you are at it.
-Chris
Hello! I've tried that Technics 615 Cassette Deck, it does work, but when compared even to my cheap JVC mini hi-fi tape deck, it falls short (with the same cassette, an Alan Parson's Project album). It does have a muffled, boomy and distorted sound. What's causing this? I've cleaned the heads with normal alcool, not sure about how recondition them... Maybe I have to replace them, but I'm not sure what's the problem. I've also tried without dolby NR, and it does give a more open sound, but it lacks everything that's over 1kHz.
You can play a little with azimuth and try to demagnetize the head. Other than that you can replace the head. It shouldn't be expensive.
Playing the tape with DolbyNR on makes sense only if the tape is recorder with Dolby. I don't recall if this deck has both Dolby B and C, but think not.
Speaking of decks I have RSB-465 and few hunderd tapes and haven't listened a single one for last few years. It is one of those dust collectors I am collecting. Together with MiniDisc.
Playing the tape with DolbyNR on makes sense only if the tape is recorder with Dolby. I don't recall if this deck has both Dolby B and C, but think not.
Speaking of decks I have RSB-465 and few hunderd tapes and haven't listened a single one for last few years. It is one of those dust collectors I am collecting.
Together with MiniDisc.
Aaaarghhhh! Ten minutes ago I plugged the tape deck into my amp and stroke "play"... I've got a very high oscillation sound, not dependent of my amp (because it does the same when the deck is unplugged) and the VU meters on the deck go on the max. What can cause a tape deck to oscillate if some hours ago it didn't?
Hi Giaime,
The record play switch has dirty contacts. This may be a long switch or a relay. If it's a relay, cleaning it will be temporary, don't replace it until everything else is working properly.
Do not correct the azimuth (head angle, 0° = perpenticular to the side of the tape) unless you know for sure there is no path worn in the head. Use your fingernail and pull it from bact to front. Any ridge indicates wear.
Check the capstan bearing for wear and relubricate now. The oils are not effective at this time and the bearing will wear quickly if you use it now.
If the deck has ferrite heads, visible wear occurs slowly, but the actual head gap "chips" wide and HF response goes down.
-Chris
The record play switch has dirty contacts. This may be a long switch or a relay. If it's a relay, cleaning it will be temporary, don't replace it until everything else is working properly.
Do not correct the azimuth (head angle, 0° = perpenticular to the side of the tape) unless you know for sure there is no path worn in the head. Use your fingernail and pull it from bact to front. Any ridge indicates wear.
Check the capstan bearing for wear and relubricate now. The oils are not effective at this time and the bearing will wear quickly if you use it now.
If the deck has ferrite heads, visible wear occurs slowly, but the actual head gap "chips" wide and HF response goes down.
-Chris
Thanks! Cleaning the switch didn't help, and I don't know if it's linked to a relay, there are 2 black rectangular things on the board that seem to be relays, but they don't make that relay "click" when I push play. And I noticed that when the RCA cable to my amp is connected, the oscillation waits a moment before starting, and with the cable disconnected it starts to oscillate immediatly when I push play.
I won't correct the azimuth because I can't find an adjust screw, and yes, the head seems to have many scratches now that I removed the screws that holds it in place. They are vertical scrathces (I mean not parallel to the tape). It's the worn head that's causing oscillation and it needs replacing or it is something else?
I won't correct the azimuth because I can't find an adjust screw, and yes, the head seems to have many scratches now that I removed the screws that holds it in place. They are vertical scrathces (I mean not parallel to the tape). It's the worn head that's causing oscillation and it needs replacing or it is something else?
Hi Giaime,
The relay would engage when you go into record mode. Why not try that a few times to see if it clears up?
I have only seen an open head cause the playback amp go into oscillation. Bad contacts add resistance to that connection, so the playback amp oscillates for the same reason.
The azimuth screw is one withthe coil spring under it. Damage is done, put a tape in after reassembling the head. Screw the post side down, not overtight and put some nail polish on it. Make the head roughly parallel to the transport. The first tape is an old one you don't want. Play it and adjust the spring side for max highs. Once that is done, use some better tapes and adjust the same screw for max highs. Use the normal setting if the highs are hard to hear. Put some nail polish on that screw when done.
Leave the deck for a few hours before doing anything else so your adjustment doesn't drift.
-Chris
The relay would engage when you go into record mode. Why not try that a few times to see if it clears up?
I have only seen an open head cause the playback amp go into oscillation. Bad contacts add resistance to that connection, so the playback amp oscillates for the same reason.
The azimuth screw is one withthe coil spring under it. Damage is done, put a tape in after reassembling the head. Screw the post side down, not overtight and put some nail polish on it. Make the head roughly parallel to the transport. The first tape is an old one you don't want. Play it and adjust the spring side for max highs. Once that is done, use some better tapes and adjust the same screw for max highs. Use the normal setting if the highs are hard to hear. Put some nail polish on that screw when done.
Leave the deck for a few hours before doing anything else so your adjustment doesn't drift.
-Chris
I've had the same problem with oscillations. They were fixed, but can't tell you how. It was 15 years ago. Somebody repaired it for me. As I recall when I pressed play, VU meters jumped to some +3dB and sound of osc. was very high. I remember that I was pushing play/stop few times and osc. were gone.
Azimuth? Record a sine tone of 1kHz to the tape using recorder you can trust. Connect DVM to the output and measure output voltage while changing the azimuth. Try to get same voltage (the higher the better) on both outputs.
If you have an access to the scope try to get them in the phase. Anatech already explained you the way of adjusting azimuth.
Azimuth? Record a sine tone of 1kHz to the tape using recorder you can trust. Connect DVM to the output and measure output voltage while changing the azimuth. Try to get same voltage (the higher the better) on both outputs.
If you have an access to the scope try to get them in the phase. Anatech already explained you the way of adjusting azimuth.
Hi Tomislav,
All tape decks record off azimuth, some can be corrected like three head Nakamichi and some three head Teac / Tascam (122MKII). The only tape deck I trust are azimuth test tapes from people like Nak and Teac.
Your osc. problem was the same thing. Very common with earlier machines until they went with solid state switching.
-Chris
All tape decks record off azimuth, some can be corrected like three head Nakamichi and some three head Teac / Tascam (122MKII). The only tape deck I trust are azimuth test tapes from people like Nak and Teac.
Your osc. problem was the same thing. Very common with earlier machines until they went with solid state switching.
-Chris
Well, the oscillation problem is fixed (don't know how I did it), but the head misses any adjustation screw. There isn't a screw with a coil under it: the head is fixed by 2 screws on a plastic thing that moves when I hit play. No adjust at all.
Anyway I tried to replace the head with one I found in my junk bin with little results. I don't know how I wired it, I just copyied the original wiring of the previous head (there are four wires: 2 red and white. There are four contacts on the head: red on the lower ones and white on the upper. Is that correct? I even found an head with 6 contacts. How can I wire it?). The sound now is more open, but I believe I missed something because there's big hiss and the sound appears to be mono (the VU now are moving toghether, before they didn't). I suppose I have to buy a new head (or you could just tell me how to wire the 6 contacts one that appears to be bigger and higher quality.)
Edit: that bigger head has 8 (!) contacts. Four per side. Two on one side are joined toghether with a solder blob. The others are linked to a switch that I believe is doing some sort of phase select. I've draw something to explain:
Anyway I tried to replace the head with one I found in my junk bin with little results. I don't know how I wired it, I just copyied the original wiring of the previous head (there are four wires: 2 red and white. There are four contacts on the head: red on the lower ones and white on the upper. Is that correct? I even found an head with 6 contacts. How can I wire it?). The sound now is more open, but I believe I missed something because there's big hiss and the sound appears to be mono (the VU now are moving toghether, before they didn't). I suppose I have to buy a new head (or you could just tell me how to wire the 6 contacts one that appears to be bigger and higher quality.)
Edit: that bigger head has 8 (!) contacts. Four per side. Two on one side are joined toghether with a solder blob. The others are linked to a switch that I believe is doing some sort of phase select. I've draw something to explain:
Attachments
Giaime,
For now put the original head back in it. Please.
There are different materials used in heads and each has different compensation, for record too. You can't properly switch them around. Then there are autoreverse heads with four gaps, bonded heads with a separate rec head bonded to a play head. Then there are the horrible "flippy heads" used in newer cheap autoreverse machines. These spin on a gear. Azimuth correction is accomplished with a screw in the housing.
Just a friendly suggestion to get things working before playing with more difficult stuff.
-Chris
For now put the original head back in it. Please.
There are different materials used in heads and each has different compensation, for record too. You can't properly switch them around. Then there are autoreverse heads with four gaps, bonded heads with a separate rec head bonded to a play head. Then there are the horrible "flippy heads" used in newer cheap autoreverse machines. These spin on a gear. Azimuth correction is accomplished with a screw in the housing.
Just a friendly suggestion to get things working before playing with more difficult stuff.
-Chris
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