Hi,
I have a Sony TA-E86 preamp that has a little problem (I hope). 🙁
When using any of the line inputs, there's sound on the left channel only. There's just hum in the right channel. When I switch the mono?stereo selector to MONO, sound comes out from both speakers. When I use the tape input, with the SOURCE/TAPE switch switched to TAPE, it is normal, both in mono or stereo. Any advice will be appreciated. Thanks.
I have a Sony TA-E86 preamp that has a little problem (I hope). 🙁
When using any of the line inputs, there's sound on the left channel only. There's just hum in the right channel. When I switch the mono?stereo selector to MONO, sound comes out from both speakers. When I use the tape input, with the SOURCE/TAPE switch switched to TAPE, it is normal, both in mono or stereo. Any advice will be appreciated. Thanks.
Pease huming in one of the speakers is a sign that there is no signal to the input of that channel........ trubleshoot that channel by back tracing it.
Have a close look at the source selector switch...
I have two of these units.
If I were in your shoes, I'd have a close look to the source selector switch.
Cleaning or repairing it may be at order - it gave me grief (dropping/muting out channels randomly) in both units, after they had been sitting in the shelf unused for some time. In my case, cleaning did the job.
Best regards,
Micha
===
I have two of these units.
If I were in your shoes, I'd have a close look to the source selector switch.
Cleaning or repairing it may be at order - it gave me grief (dropping/muting out channels randomly) in both units, after they had been sitting in the shelf unused for some time. In my case, cleaning did the job.
Best regards,
Micha
===
"Originally posted by cchean
Hi,
I have a Sony TA-E86 preamp that has a little problem (I hope).
When using any of the line inputs, there's sound on the left channel only. There's just hum in the right channel. When I switch the mono?stereo selector to MONO, sound comes out from both speakers. When I use the tape input, with the SOURCE/TAPE switch switched to TAPE, it is normal, both in mono or stereo. Any advice will be appreciated. Thanks. "
Did you ever find the problem with your preamp? Mine is doing exactly the same.
Robt.
Hi,
I have a Sony TA-E86 preamp that has a little problem (I hope).
When using any of the line inputs, there's sound on the left channel only. There's just hum in the right channel. When I switch the mono?stereo selector to MONO, sound comes out from both speakers. When I use the tape input, with the SOURCE/TAPE switch switched to TAPE, it is normal, both in mono or stereo. Any advice will be appreciated. Thanks. "
Did you ever find the problem with your preamp? Mine is doing exactly the same.
Robt.
Actually there are two input selector switches mechanically
coupled with a metal stick.
This coupling can get wrong due to old plastic of the switches.
The connection has to be repaired.
This preamp also has the problem of aggressive glue used for
fixing wires on the copper side of the board. This can lead to
intermittent copper traces with loss of signal in one phono channel.
Easiest fix is a wire from hot phono input RCA socket to the
respective point of the "Phono" switch.
coupled with a metal stick.
This coupling can get wrong due to old plastic of the switches.
The connection has to be repaired.
This preamp also has the problem of aggressive glue used for
fixing wires on the copper side of the board. This can lead to
intermittent copper traces with loss of signal in one phono channel.
Easiest fix is a wire from hot phono input RCA socket to the
respective point of the "Phono" switch.
Not a very actual topic anymore, but the notification of wear and nasty glue is appreciated. I own two: one playing now (bought at 'sale-day' long ago) and one 2nd hand with desastrous mods made by an alien. For sale for scrap value (=zero).
Sorry that I posted this, but people are constantly looking for schematics
and repair tips here on DIYA forum.
The RIAA equalisation is excellent. Main output 2 has a fixed bass lift.
and repair tips here on DIYA forum.
The RIAA equalisation is excellent. Main output 2 has a fixed bass lift.
The Service Man is on the HifiEngine proper. Nice explanations of how those circuits work. Well build preamps E86 and E88, but the power amps N86 (mine in almost constant repair) and the N88 (Vfets! Not broken, yet...?) are not for the faint hearted. The 'Bass-boost' output 2 of the E86 can be modified, eg as an recout buffer. Never understood why Sony made this odd deviation with this amp. Output 1 is straight and can drive up to 50Vpp = 16.5V~ on 8kΩ loads flawlessly. 26dB headroom: just name one other.
The glue in my pre's is in good condition, and so the tracks underneath.
The third picture shows this 'bass-boost' circuit. The three red caps and the four resistors just on the right side of them is the double T-network lifting 120Hz 6dB up. Notice just left of this three red caps is the input jfet of this stage: 2SK42. It's specs say Vdsmax = 15 or 20V, but it runs on 30V... for many years now. Idset is only 60μA.
The third picture shows this 'bass-boost' circuit. The three red caps and the four resistors just on the right side of them is the double T-network lifting 120Hz 6dB up. Notice just left of this three red caps is the input jfet of this stage: 2SK42. It's specs say Vdsmax = 15 or 20V, but it runs on 30V... for many years now. Idset is only 60μA.