Hi all,
I recently picked up an Akai preamp. Lovely thing with a nice build quality. Sounds pretty OK too. Anyway, I had the cover off (as you do!!) and was wondering what the hitachi devices in the middle of the board were.
See the ones, marked L23, green and with the hitachi logo. Couldn't find anything on a search for them.
Anyone recognise them?
Its an Akai PR-A06 - don't suppose theres a service manual knocking about (again, search only showed pay sites)
Fran
I recently picked up an Akai preamp. Lovely thing with a nice build quality. Sounds pretty OK too. Anyway, I had the cover off (as you do!!) and was wondering what the hitachi devices in the middle of the board were.
See the ones, marked L23, green and with the hitachi logo. Couldn't find anything on a search for them.
Anyone recognise them?
Its an Akai PR-A06 - don't suppose theres a service manual knocking about (again, search only showed pay sites)
Fran
Attachments
i wonder how possible is that this machine "sounds nice " when its obvious with a naked eye that has more than one capacitor on the power supply boiled to deep fried
presumambly most of other capacitors inside will have more or less same or similar problems ....
often we see and read coments that machine A or machine plays fantastic or amazing and bla bla bla .... that could be truth if compaired to a the previous system that was an ipod with creative speakers ....or something like that ...
back to earth ....for a machine that is builted like that and electric wise most if not all caps have to be replaced ....given the oportunity better quality and more capacitance will make things by far better in a lot of stages .....
benefit from the relays and lighten up wiring and may also play with bandwidth and or other capacitor based limitations and this machine could easily reach hiend standards ...
not a lot of money but for sure a lot of expert work to be done to get there
kind regards Sakis
presumambly most of other capacitors inside will have more or less same or similar problems ....
often we see and read coments that machine A or machine plays fantastic or amazing and bla bla bla .... that could be truth if compaired to a the previous system that was an ipod with creative speakers ....or something like that ...
back to earth ....for a machine that is builted like that and electric wise most if not all caps have to be replaced ....given the oportunity better quality and more capacitance will make things by far better in a lot of stages .....
benefit from the relays and lighten up wiring and may also play with bandwidth and or other capacitor based limitations and this machine could easily reach hiend standards ...
not a lot of money but for sure a lot of expert work to be done to get there
kind regards Sakis
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Look at the pcb tracks to the north of the relays - they go straight to the chassis input sockets!
Much easier and shorter path lengths to switch the relay coils (DC) via the fron panel switches.
#
Sakis, would you mind pointing out the offending cap - I'm obviously missing something because I can't see it.
And for what its worth, I said it
not that its hi-end unbelieveably good.
Thanks for the help guys - never saw relays like that before. That indeed is how the inputs are switched - plus some of the other stuff too.
Its a massive motorised volume pot - there are up and down switches at the front panel and you can hear it whirr when you adjust volume. Theres also an LED display for the volume level. Front panel pic is attached.
The white belt - do you mean the ribbon cable?
Fran
Attachments
Righto, i knew it was called something like that.
Pretty OK phono stage, NEC willy JFETs, very up-town for an AKAI, shame the brand chose a different approach later on.
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Ah, very good - couldn't see that.
I'll open up the case again and have a better look. I just had a good zoom in on the hi-res photo and the bottom one in the above pic does look swollen up alright. The other one isn't as bad but who knows. Given that theres a reasonably large heatsink just around there, maybe those caps have had a tougher time of it.
Anyhow, it still does sound pretty OK. It wouldn't have the refinement of say, my aikido, or the absolute surefootedness of the DCB1..... but it rocks well. And the phonostage bit is definitely above average (only tried with MC).
Fran
I'll open up the case again and have a better look. I just had a good zoom in on the hi-res photo and the bottom one in the above pic does look swollen up alright. The other one isn't as bad but who knows. Given that theres a reasonably large heatsink just around there, maybe those caps have had a tougher time of it.
Anyhow, it still does sound pretty OK. It wouldn't have the refinement of say, my aikido, or the absolute surefootedness of the DCB1..... but it rocks well. And the phonostage bit is definitely above average (only tried with MC).
Fran
now that i ve seen the front ...i remember i have only repaired one of this only ( so far )
well ... this machine had a potential to be something really nice its actually not ...even though seems that akai at the time had in mind reed relays it seems that these are applyied as a function in the output stage ...( probably to control the matching eq of the series )
that will not make an ultraquiet machine more than one active source in the input and cross talk figures are more or less terible .. stil bandwidth and driveabilty is good and its not realy realy uncoloured but japanese where never good there ( in comercial equipment ) still 90khz square wave was looking good in the output of this preamp ...too good i think for this type of machine
yeap the volume is kind fancy ...and yes looking for a schematic was a dead end ...
as about the phono stage i didnt actually payed much of attention there at the time ...
all story rings a bell i thing i have placed an article in the past regarding the matching amplifier and the nightmare that was inside ....let me see
well ... this machine had a potential to be something really nice its actually not ...even though seems that akai at the time had in mind reed relays it seems that these are applyied as a function in the output stage ...( probably to control the matching eq of the series )
that will not make an ultraquiet machine more than one active source in the input and cross talk figures are more or less terible .. stil bandwidth and driveabilty is good and its not realy realy uncoloured but japanese where never good there ( in comercial equipment ) still 90khz square wave was looking good in the output of this preamp ...too good i think for this type of machine
yeap the volume is kind fancy ...and yes looking for a schematic was a dead end ...
as about the phono stage i didnt actually payed much of attention there at the time ...
all story rings a bell i thing i have placed an article in the past regarding the matching amplifier and the nightmare that was inside ....let me see
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ok found the article ...enjoy ( helllo Jacco !!! how are you doing ??? )
http://www.diyaudio.com/forums/solid-state/126944-greek-repair-akai-pa-w-06-a.html
it will be very very funny to spent a moment and read the principal of opeartion for the repair of the amplifier ....very very funny... here http://www.diyaudio.com/forums/solid-state/126944-greek-repair-akai-pa-w-06-a.html#post1578069
http://www.diyaudio.com/forums/solid-state/126944-greek-repair-akai-pa-w-06-a.html
it will be very very funny to spent a moment and read the principal of opeartion for the repair of the amplifier ....very very funny... here http://www.diyaudio.com/forums/solid-state/126944-greek-repair-akai-pa-w-06-a.html#post1578069
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Friend Sakis,
i was doing fine, untill i checked the current temperature forecast at your side. (think i'll put on my grandmother's Long Johns today)
Deep Sigh => http://commondatastorage.googleapis.com/static.panoramio.com/photos/original/26826113.jpg
Speaking of MIT, couldn't resist : http://www.icms.polyu.edu.hk/ifspa2010/CV/Bio_HEHaralambides[2010].pdf
(least he graded me was an A-, who ever said going Greek is painfull must have been kidding.
)
i was doing fine, untill i checked the current temperature forecast at your side. (think i'll put on my grandmother's Long Johns today)
Deep Sigh => http://commondatastorage.googleapis.com/static.panoramio.com/photos/original/26826113.jpg
Speaking of MIT, couldn't resist : http://www.icms.polyu.edu.hk/ifspa2010/CV/Bio_HEHaralambides[2010].pdf
(least he graded me was an A-, who ever said going Greek is painfull must have been kidding.
)
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