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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc. |
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27th Jan 2019, 9:07 am | #1 |
Retired Dormant Member
Join Date: Jan 2019
Location: Melbourne, Victoria, Australia.
Posts: 3
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Akai 4000DS MK-II
I have an Akai 4000DS which seems largely indestructible. However a small problem I recently discovered is that the outputs (RCA & 5 pin) only carry the left signal to the amplifier (the right channel seems completely dead on both outputs) however when I plug in the headphones, both channels work fine in stereo. I suspect it is not a problem with the heads but somewhere else. Does anyone have any suggestions (or can refer me to a previous thread if one exists) for this problem? I am a novice, but I can fix simple things. They seem great machines to tinker with.
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27th Jan 2019, 6:31 pm | #2 |
Nonode
Join Date: Jun 2014
Location: Bristol, UK.
Posts: 2,074
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Re: Akai 4000DS MK-II
Great machines - I have had mine from new in 1975! Both phones and line out should be the same level so that's odd. You are not using the same lead (DIN one end, RCA the other) are you? The problem could be with the lead if that's the case.
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28th Jan 2019, 2:02 am | #3 |
Retired Dormant Member
Join Date: Jan 2019
Location: Melbourne, Victoria, Australia.
Posts: 3
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Re: Akai 4000DS MK-II
Thanks for this. I began with a set of RCA plugs from the output into the amplifier. Swapped them around to confirm which channel wasn’t working. I removed the leads and then tried a lead which is DIN on one end and RCA at the other end. Tested again and same channel not working. Plugged in the headphones at the same time, and through the headphones it works perfectly in stereo. I haven’t yet taken the machine apart to look inside, but that is probably the next step.
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1st Feb 2019, 11:06 pm | #4 |
Tetrode
Join Date: Sep 2013
Location: Farnham, Surrey, UK.
Posts: 50
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Re: Akai 4000DS MK-II
Hello. I have looked at a diagram. The last transitor TR8 feeds the VU meter/s (via a Diode etc) and the headphone/s (via transformer) and the line out RCA socket/s via a single 15k resistor/s. The DIN socket pin 3 left and pin 5 right are further reduced in level by 9.1k and 18k resistors to earth.
If the headphones work normally and the VU meters work (you didn't say) the only possible fault is an open circuit somewhere near R13 which is the 15k (Not on the circuit board, probably on the back of the phono socket) or the connection to the edge of the board (white wire Left) and (grey wire Right). My diagram is a MK2 but a rotten copy so I hope I got it right. I agree the 4000 series are good machines. The IC2 and IC2b - LD-3141 IC's get noisy with sudden crackles (see other posts) replacements are available. I have a DB which is one of the best sounding 1/4 tracks at low speeds that I have heard. Good luck. Good luck. |
6th Feb 2019, 12:23 pm | #5 |
Retired Dormant Member
Join Date: Jan 2019
Location: Melbourne, Victoria, Australia.
Posts: 3
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Re: Akai 4000DS MK-II
Thank you Gordonv54. Yes, the VU meters work fine, so your diagnosis makes perfect sense. I appreciate the advice. It will be several weeks before I get back to it, but will update this post on any progress I make.
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