I am thinking about engaging in the somewhat monumental task of completely rebuilding my E-202, which my local repairman wants $1200+ to do.
Does anyone here have experience with servicing one of these?
Does anyone here have experience with servicing one of these?
I would post photos, a link to schematic / service manual as well.
IIRC they are top end Japanese sets.
Not many sold, may have unusual parts inside.
IIRC they are top end Japanese sets.
Not many sold, may have unusual parts inside.
We specialize in restoring vintage amplifiers/preamplifiers. Almost all our restorations involve replacing all audio circuit resistors, capacitors and ICs.
Time consuming, of course but well worth the effort. Japanese amplifiers are tough to work on due to single sided PCBs and each PCB has many wires connecting to it. Make lots of diagrams and take photos.
The output transitors, if bad, are no longer available and you will be forced to use ON-SEMI MJ series.
The main split rail caps are mostly a head ache due to wierd sizes used. This uses 10,000mfd 63v types and normally these come in 50mm diameter cans, but not always.
Most times we increase the value of these capacitors and then we use one of our in house designed surge limiting circuits to prevent destruction of the power switch. Recently did a McIntosh MC2105, replaced their ugly drive board with again our in house designed fully complementary boards and replaced the 39,000mfd 40v rail caps with 150,000mfd 50v types which of course demanded the surge circuit.
The JFets used in the E202 are obsolete. Hope they are not bad.
I have worked on Accuphase from my days in South Africa so I am well versed in their designs.
Steve Mantz
Zed Audio Corp
www.zedaudiocorp.com
Time consuming, of course but well worth the effort. Japanese amplifiers are tough to work on due to single sided PCBs and each PCB has many wires connecting to it. Make lots of diagrams and take photos.
The output transitors, if bad, are no longer available and you will be forced to use ON-SEMI MJ series.
The main split rail caps are mostly a head ache due to wierd sizes used. This uses 10,000mfd 63v types and normally these come in 50mm diameter cans, but not always.
Most times we increase the value of these capacitors and then we use one of our in house designed surge limiting circuits to prevent destruction of the power switch. Recently did a McIntosh MC2105, replaced their ugly drive board with again our in house designed fully complementary boards and replaced the 39,000mfd 40v rail caps with 150,000mfd 50v types which of course demanded the surge circuit.
The JFets used in the E202 are obsolete. Hope they are not bad.
I have worked on Accuphase from my days in South Africa so I am well versed in their designs.
Steve Mantz
Zed Audio Corp
www.zedaudiocorp.com
If the Jfets you are referring too are the small signal transistors, at least several are bad, and I was told to replace them all. The circuit blocks are plug-in card types.
Then you will have to search far and wide to find substitutes. If I was doing this restoration I would substitute the JFETs with pairs of Darlington bipolar transistors (In order to maintain the high input impedance),
Thanks for all of your help. I have decided to go in a different direction for now by building a Pass amp clone.
Even if you enjoy the Pass clone now, Accuphase E-202 is useful enough to be preserved.
Read also here : https://www.diyaudio.com/community/...iagrams-repair-etc.211108/page-2#post-3558815
Most of the time your work should not be a "somewhat monumental task of completely
rebuilding", because the parts quality is high, I would only address actually failed parts.
Have a look for overheated resistors.
Read also here : https://www.diyaudio.com/community/...iagrams-repair-etc.211108/page-2#post-3558815
Most of the time your work should not be a "somewhat monumental task of completely
rebuilding", because the parts quality is high, I would only address actually failed parts.
Have a look for overheated resistors.
Selling your amp " as is ", and they still go for decent price and buying already restored one for around $1k is also an option if you want the piece and task looks monumental.
Thank's for your response, but I didn't buy the clone. One thing that scares me is the evaporating copper trace you spoke of. People have mentioned that these are difficult to solder.
The amp just sits in the bottom of my closet for now.
No one has been able to diagnose what is wrong with it specifically. But all agree that it needs a complete rebuild.
Is it playing music on both channels?
When you switch it on, volume set at zero, do you hear thé speaker relay engaging?
You should hear one click after a few seconds.
If so, this indicates that maybe there are no serious problems.
When you switch it on, volume set at zero, do you hear thé speaker relay engaging?
You should hear one click after a few seconds.
If so, this indicates that maybe there are no serious problems.
It's outputing nothing whatsoever from any part of it even with the relay locked to the on
position.
position.