I have a Sony Ta-n77es and I am experiencing a problem. When I power it in fixed mode everything works mono and stereo but when I switch to variable, the right channel goes away and turning the right attentuator gives almost no sound. My assumption is the right attentuator is bad but im not sure. Anything appreciated. I have take it apart and I was wondering if there is a way to test the volume attentuator to see if it is the problem.
Sony Ta-n77es
- Thread starter TVV
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The attenuators themselves are simple 20K pots (potentiometers). If you have an ohmmeter, you could verify that you measure 20,000 ohms between the two outer terminals of the pot, and somewhere between 0 and 20,000 between the center terminal and either of the outer ones. (The latter measurements will depend on where the attenuator is set.) You need to make this kind of test with the power off. Luckily, the variable inputs are disconnected in the power-off state, so there won't be anything to "confuse" the ohmmeter readings.
I think it is more likely that there's a connection problem, either between the variable input jacks and the attenuator, or between the attenuator and the amplifier input. You could test the first connection by using the ohmmeter to measure between the center and ring terminals of the variable input jacks, again with the power off. That measurement should be 20,000 ohms.
The second connection, between the attenuator and the amplifier input, is made by a relay that engages when you switch to variable. If the above tests don't detect any problems, then I think it's a fair bet that the relay is bad.
Hope this helps,
chazix
I think it is more likely that there's a connection problem, either between the variable input jacks and the attenuator, or between the attenuator and the amplifier input. You could test the first connection by using the ohmmeter to measure between the center and ring terminals of the variable input jacks, again with the power off. That measurement should be 20,000 ohms.
The second connection, between the attenuator and the amplifier input, is made by a relay that engages when you switch to variable. If the above tests don't detect any problems, then I think it's a fair bet that the relay is bad.
Hope this helps,
chazix
restorer-john
Addicted Member
This is perfectly normal.There is nothing wrong with your amp.
It is not a mono function switch like on a preamplifier, it is a BTL (balanced tied load) operation for the amplifier. ie. it turns the TAN77es into one (1) super powered mono amplifier (580w@8ohms). Output in BTL mode is from the two + (positive) terminals of the left and right channels. You would of course need two TAN77es amplifiers in BTL mode for stereo.
Trust me, you'd never need two running in bridge mode...
It is not a mono function switch like on a preamplifier, it is a BTL (balanced tied load) operation for the amplifier. ie. it turns the TAN77es into one (1) super powered mono amplifier (580w@8ohms). Output in BTL mode is from the two + (positive) terminals of the left and right channels. You would of course need two TAN77es amplifiers in BTL mode for stereo.
Trust me, you'd never need two running in bridge mode...
You are right of course, but my impression was that the OP's question had to do with the front panel fixed/variable switch, not the rear panel stereo/mono switch.
@TVV, can you clarify whether you are doing anything with the rear panel stereo/mono switch? If you only have one TA-N77ES, you would always want that switch set to stereo.
Cheers,
chazix
restorer-john
Addicted Member
Yes, I read his question as running the amp in mono, where the input attenuator is only effective for the left channel, the right is bypassed and the signal is fed to the inverting input to the differential FET pair in the front end via a relay.
He needs to clarify as the fixed/variable relay could be dirty (they are touchy little buggers).
He needs to clarify as the fixed/variable relay could be dirty (they are touchy little buggers).
_Hola a todos, último mensaje 4 julio 2017 .......
_que bonito es preguntar y quejarse de no tener ayuda
_que bonito es tener respuestas y desaparecer
_es tan fácil preguntar y obtener una idea del camino a seguir con preguntas y respuestas
_las personas toman su tiempo para ofrecer ayuda y otras recogen ese tiempo donde al solucionar su problema se desvanecen
_gracias por vuestro tiempo, gracias por vuestras respuestas, gracias por el granito de arena que aportáis para otras personas
_gracias por vuestras respuestas para un futuro propietario de un sony ta-n77es ...... estare leyenso sobre este equipo para futuros mantenimientos
_que bonito es preguntar y quejarse de no tener ayuda
_que bonito es tener respuestas y desaparecer
_es tan fácil preguntar y obtener una idea del camino a seguir con preguntas y respuestas
_las personas toman su tiempo para ofrecer ayuda y otras recogen ese tiempo donde al solucionar su problema se desvanecen
_gracias por vuestro tiempo, gracias por vuestras respuestas, gracias por el granito de arena que aportáis para otras personas
_gracias por vuestras respuestas para un futuro propietario de un sony ta-n77es ...... estare leyenso sobre este equipo para futuros mantenimientos