picked up a Pioneer A-9 - Top of the line A series

allanmatters

allanmatters

Active Member
well i just picked up this system yesterday. I was looking high and low for a Pioneer A-7 or at least an A-8. For some reason i fell in love with these series because of the detailed sound it would give on my HPM's

I have an A-7 But after 9 months of intense work i finally gave up on it,more info on that here http://www.audiokarma.org/forums/showthread.php?t=542949

Now i have questions on this Pioneer A-9 non-switching amp i picked up from a guy.

Its beautiful . i love the power if it .
i wanted some help on the amplifier.
* like what type of transformer it has? since its like a circular cylinder and never gets hot on usage, its humongous !!

* i got it for around 183 USD . I tried to negotiate but the buyer was stubborn and said 200 usd was final. is this a decent buy?

greenshot

* also on opening the unit at home i could not see the output transistors cause they were covered by the massive shark fins heat sink.
i found out that the set was repaired on the left channel outputtransitors.

the original ones on the right side of the heat sink looked like the ones in my A-7 only difference the A-7 had 2 on each side, This A-9 had 4 on each side

these are the original ones below

adult photo sharing


and these are the equivalents i suppose. they take lesser area

screen shot windows

I tested the system for 2 days , i used the system at its full power like 99 % and my speakers were also used to 99% till the max


capture

i noticed the left heat sink was little more hot than the right , guessing its because those new equivalent transistors cant handle the heat that much ?

*will this be a problem ? of course i will not raise the volume all the way till the end until the green VU meters are hitting the red led VU meters

* so far what do you people think think on this amp? it brilliant . lovely sound at any volume level

looking for some great advice on this amp. I am currently trying to locate the entire user manual as there is so much to know about this baby
 
Last edited:
Register to hide this ad
I owned an A-8 back in the 1980's. It was a nice, clean sounding amp. One heatsink of that A-9 is probably hotter than the other because one channel is not correctly biased. You need to get the bias checked and adjusted, as well as DC offset.
 
Last edited:
I also bought a Pioneer A-7 along with a Pioneer PL-7 turntable and B&O cartridge in the early 80's. It was a clean sounding amp that I used for many years until I upgraded to a pair of Bryston 2B LP's and 0.5B preamp.
 
heating

Glen B said:
I owned an A-8 back in the 1980's. It was a nice, clean sounding amp. One heatsink of that A-9 is probably hotter than the other because one channel is not correctly biased. You need to get the bias checked and adjusted, as well as DC offset.
Click to expand...

it is barley noticable . the left side heat sink gets slightly more hotter than the right side on maximum usage of the amplifier , that is when i put the volume to the max like 110 watts, so then i touched the left heat sink(the ones in which all 4 equivalent output transistors have been put) so the left side has the equivalent transistors which are on the heatsink which gets little more hotter

the right channel has the original transistors just like the ones on my A-7.

they could have put in some Sanken transistors atleast on the left channel. little worried about this

below ares sanken transistors which matches the size of the original Toshiba rectangular looking transistors

http://iceimg.com/26bc7e47253f4e.jpg.htm
 
The A-9 has a toroidal power transformer, shaped internally like a doughnut with wire wrapped in and around it. It is more space efficient and is sort of self shielding. Many of Pioneer's TOTL models have that type of transformer.

I'd say $183 was a pretty good price for this model, if you like them as I do. Not as nice looking to some without the previous thick aluminum faceplates but still a very capable unit, and forerunner of the A77X-A88X models that would lead to the Elite series.

I would agree that, assuming the unit was repaired correctly with good equivalent transistors and peripheral parts, the unit should be checked for DC offset and then bias settings. Finding the service manual will be the big issue so you may have to check with any Pioneer outlet in Japan, the US or UK, or Germany, to see if anyone has it. Or maybe get the service manual for the A-7 or A-8 or the AxxX models above and see if they give some ideas. I suspect the units are structurally and possibly electronically similar.

BTW, remind us again where in the world you are in case some referrals need to be made.
 
I had an thrift A-9 for a brief period before it died.I liked it but cosmetically it was not that good so I didn't bother with it and gave it away.I did like it though.
 
The A9 was part of the Pioneer Champagne series, created to go with their new acquisition, Phase Linear. The series did not last. I guess folks did not like champagne colored plastic. I have a complete chanpagne set I will put together and restore one day soon (TT, tape deck, amp, preamp, tuner, etc.).

Enjoy,
Rich P
 
power fluctuations

mech986 said:
The A-9 has a toroidal power transformer, shaped internally like a doughnut with wire wrapped in and around it. It is more space efficient and is sort of self shielding. Many of Pioneer's TOTL models have that type of transformer.

I'd say $183 was a pretty good price for this model, if you like them as I do. Not as nice looking to some without the previous thick aluminum faceplates but still a very capable unit, and forerunner of the A77X-A88X models that would lead to the Elite series.

I would agree that, assuming the unit was repaired correctly with good equivalent transistors and peripheral parts, the unit should be checked for DC offset and then bias settings. Finding the service manual will be the big issue so you may have to check with any Pioneer outlet in Japan, the US or UK, or Germany, to see if anyone has it. Or maybe get the service manual for the A-7 or A-8 or the AxxX models above and see if they give some ideas. I suspect the units are structurally and possibly electronically similar.

BTW, remind us again where in the world you are in case some referrals need to be made.
Click to expand...


thank you for your advice mech, i hope to find someone reliable to check the DC offset and bais current.

As if now the last thing on my mind is the power fluctuations which happens only during the late evening hours at my place.
I have power cuts which go on off and on sometimes like for 10 mins or maximum half an hour

however during the late evening hours when my system is running there are certain power fluctuations that take place, so when this happens while the music is playing , the VU meters drop down nil with no signal at times , sometimes the left VU meter is down or both are nil with no signal but the music plays perfectly and then it comes back on it s own randomly.

another thing i noticed when buying this unit is the protection LIGHT .which is supposed to blink red on for 3-4 seconds when u switch on the system and then turns green (just like in my A-7)
the light does not work, however the relays click properly. so when the power fluctuates the sound stops on my A-9 and the relay clicks. i suppose the protection mode is in play at that time. so by the relay sound i assume all this because the light indicator is not working. and then when the power becomes stable the relays unclick and the sound of the music continues playing

so is the built protection circuitry good enough for handling the power fluctuations ? OR do i need to get a stabilizer for safety ??


for your information i have an inverter battery at home but does not have the UPS function (uninterrupted power supply) i plan on getting a newer one though , but for now i have a 1.2 amperes stabilizer which is used for my LED t.v

how many amperes do i need to have when purchasing a stabilizer for my Pioneer A-9 , a DVD player and lets say a record player in the future ???

thanks allot folks for your opinions so far.
 
pustelniakr said:
The A9 was part of the Pioneer Champagne series, created to go with their new acquisition, Phase Linear. The series did not last. I guess folks did not like champagne colored plastic. I have a complete chanpagne set I will put together and restore one day soon (TT, tape deck, amp, preamp, tuner, etc.).

Enjoy,
Rich P
Click to expand...
 
Last edited:
thanks for the information :)

pustelniakr said:
The A9 was part of the Pioneer Champagne series, created to go with their new acquisition, Phase Linear. The series did not last. I guess folks did not like champagne colored plastic. I have a complete chanpagne set I will put together and restore one day soon (TT, tape deck, amp, preamp, tuner, etc.).

Enjoy,
Rich P
Click to expand...
GREAT ! id love to see the set up of yours .
 
allanmatters, congratulations on your find/acquisition.

If all the gee-gaws are working and the unit's in good cosmetic condition, that's a good price. I have an A9 at the heart of my Pioneer Communication Series (Champagne) set-up, paired with the other TOTL units from that series, driving (as of this weekend) a set of HPM-1100s. I couldn't be happier with it.

Other folks far more qualified than I have already given you suggestions on the heat sink/technical questions, so I'll limit my reply to two items:

1. Scans of the Owner's and Service Manuals for the A9 can be found online. I have a set, so PM me if you cannot locate a downloadable copy.

2. If you like this style, put together your own collection. It looks great as a set...

attachment.php


Enjoy!
 
dream

rallison said:
allanmatters, congratulations on your find/acquisition.

If all the gee-gaws are working and the unit's in good cosmetic condition, that's a good price. I have an A9 at the heart of my Pioneer Communication Series (Champagne) set-up, paired with the other TOTL units from that series, driving (as of this weekend) a set of HPM-1100s. I couldn't be happier with it.

Other folks far more qualified than I have already given you suggestions on the heat sink/technical questions, so I'll limit my reply to two items:

1. Scans of the Owner's and Service Manuals for the A9 can be found online. I have a set, so PM me if you cannot locate a downloadable copy.

2. If you like this style, put together your own collection. It looks great as a set...

attachment.php


Enjoy!
Click to expand...

wow thats like the dream !! look at those systems . mine is like just an an A-9 . my dad had the F-9 tuner too, cant believe he threw it away , id still kill for a F-9 tuner to match it, cassettes i have never used so only my dad would love owning that matching pioneer cassette player.

my system is kept across the room opposite side. The only flaw withe the A-9 i had bought was the cover on top. The last strip of holes were almost eaten up by acid. I used zero value sandpaper both the sides of the strip and then painted it black. I said to my self rather paint all the fins just like that


free uploader


free picture upload
 
Given the corrosion on the top vents, that's a pretty reasonable way to handle it. This vintage can be found almost everywhere, even if it shows up infrequently; keep an eye out for someone listing an A-9 "as-is / for parts or repair" and use the case to replace yours... It took me many months to pull together all those components, some from AK users, some from other sites. Scour used gear shops if there are any nearby you--you never know. But yes, the real gem of the series is the A-9, and it sounds like the one you've got works fine. Enjoy!
 
just months?

rallison said:
Given the corrosion on the top vents, that's a pretty reasonable way to handle it. This vintage can be found almost everywhere, even if it shows up infrequently; keep an eye out for someone listing an A-9 "as-is / for parts or repair" and use the case to replace yours... It took me many months to pull together all those components, some from AK users, some from other sites. Scour used gear shops if there are any nearby you--you never know. But yes, the real gem of the series is the A-9, and it sounds like the one you've got works fine. Enjoy!
Click to expand...

well i guess area of choice matters or where you live too. Here in India its impossible to find rare stuff like this. Even if you do find it, you would have to see cosmetic condition of the system. I am however lucky to the the A-9 . I never thought it was part of the champagne series.

I used the A-7 and was amazed at what detail sound it could give. So this motivated me to get the Pioneer A-9 instead of another A-7 since my A-7 was very sophisticated to repair(it was an inter-median fault after months of trial)

You did great on the collection. i thought you had these for ages well maintained . What about the speakers?? how much did you pick them up for? they look well maintained as good as new so sweet !!! 15 inch of cone there and dual supertweeters(I have replaced my HPM's super tweeters with one from my dads old cs since bothe the HPM's super tweeters were dead & i tried to fix em but dont have proper guidance) picture of the super tweeter which i took is in the pic below


post a picture

Dont know but they do the job. I never heard the originals of the HPM's super tweeters. Wonder. Cant get it here cause no one owns them . Maybe outside India

Im sorta happy with the HPM-700 as my room size is not very big + its really loud outside the house with the doors closed

I shall take your advice on that. As of now on my next trip i will get the F-9 tuner. The HPM- 1100 does looks tempting to replace.
 
allanmatters said:
well i guess area of choice matters or where you live too. Here in India its impossible to find rare stuff like this. Even if you do find it, you would have to see cosmetic condition of the system. I am however lucky to the the A-9 . I never thought it was part of the champagne series.

I used the A-7 and was amazed at what detail sound it could give. So this motivated me to get the Pioneer A-9 instead of another A-7 since my A-7 was very sophisticated to repair(it was an inter-median fault after months of trial)

You did great on the collection. i thought you had these for ages well maintained . What about the speakers?? how much did you pick them up for? they look well maintained as good as new so sweet !!! 15 inch of cone there and dual supertweeters(I have replaced my HPM's super tweeters with one from my dads old cs since bothe the HPM's super tweeters were dead & i tried to fix em but dont have proper guidance) picture of the super tweeter which i took is in the pic below

...

Dont know but they do the job. I never heard the originals of the HPM's super tweeters. Wonder. Cant get it here cause no one owns them . Maybe outside India

Im sorta happy with the HPM-700 as my room size is not very big + its really loud outside the house with the doors closed

I shall take your advice on that. As of now on my next trip i will get the F-9 tuner. The HPM- 1100 does looks tempting to replace.
Click to expand...

Allanmatters,

I would think you'd have to scour forum postings in Japan or Europe to find a concentration of them, as they just were not all that popular in the US--hence the limited 2-year production run. Though the plus side is that when you do find them they're more affordable than the prior sets.

I did have an SX-6 Receiver and CT-6 cassette player as my first new for stereo when I was young, but gave them to my sister when I thought I'd 'outgrown' them. Wish I had them back. I do still have the Polk Monitor 10s I bought back then... but no, I actively collected this set, and made a few minor repairs (replacing some switches and the cassette drive belt) and cleaned them up. I was lucky to find them all in such a short time.

I found the HPM-1100s for under $400 USD -- a real bargain with original cones. I sold a pair of HPM-900s to fund part of that purchase, and I'm not sure they make a good comparison as they had replacement paper cones; but the HPM-1100s are far, far better. They are big though, and need a good sized space to play at nominal wattage--so perhaps not a good solution for you.

The supertweeters are not too hard to find on auction sites--but my hearing is already degraded below the crossover point between the tweeter and supertweeter, so the only way I could figure out for sure that mine work was to generate a ~25kHz signal and use a decibel meter to check 'em.

Enjoy that A-9, it's a beauty and will serve you well, I think.
 
You must log in or register to reply here.
Back
Top Bottom