Yamaha Parts
Partstore.com. . . impressive selection.
Two M-45s (one General, one USA)
One C-85 (General)
One K640 Cassette
One MDX-793 Minidisc
Had a CDX-930. . .
Had another 3-head tape player with glass door. . .don't remember
the model number. . .cool, but traded it in for the second M-45 and
the K640 (plus about $100. . .I think I got the better deal).
Some of their stuff is hit or miss. it works from the beginning
and some just has problems. . .same with Sony(see my earlier
rant about Sony).
I am still going to move the transformer out of the C-85 box.
The old electronic proverb: Heat Kills! (and so does Current).
Partstore.com might have the pots that janusz is working with
down under.
Storage for extra equipment? . . .I have a "wife factor." Electronics
or Rubber Stamp/Scrap Booking!
Although I got a reward for transfering a Donna Summer LP over
to CD with shrunk down cover! She likes my equipment when
it does what she wants.
On occasion, I take over the living room and set up "MY STUFF"
with strict warnings: "TOUCH THIS AND DIE"
Focus. . . going down to the local surplus store to find connectors
and multi-cables for moving that transformer. It is like a little
space heater.
Do toloroids really dissipate that much less heat?
Chris Browne off for the night.. . . 10:00 P.M.
Partstore.com. . . impressive selection.
Two M-45s (one General, one USA)
One C-85 (General)
One K640 Cassette
One MDX-793 Minidisc
Had a CDX-930. . .
Had another 3-head tape player with glass door. . .don't remember
the model number. . .cool, but traded it in for the second M-45 and
the K640 (plus about $100. . .I think I got the better deal).
Some of their stuff is hit or miss. it works from the beginning
and some just has problems. . .same with Sony(see my earlier
rant about Sony).
I am still going to move the transformer out of the C-85 box.
The old electronic proverb: Heat Kills! (and so does Current).
Partstore.com might have the pots that janusz is working with
down under.
Storage for extra equipment? . . .I have a "wife factor." Electronics
or Rubber Stamp/Scrap Booking!
Although I got a reward for transfering a Donna Summer LP over
to CD with shrunk down cover! She likes my equipment when
it does what she wants.
On occasion, I take over the living room and set up "MY STUFF"
with strict warnings: "TOUCH THIS AND DIE"
Focus. . . going down to the local surplus store to find connectors
and multi-cables for moving that transformer. It is like a little
space heater.
Do toloroids really dissipate that much less heat?
Chris Browne off for the night.. . . 10:00 P.M.
Toroidal Transformers
gni
I am running in my two ESP P101,s 800VA 50-0-50 Antek and Avel-lundberg toroidal xformers. They do not have even a hint of heat even operating for several hours at extremely loud volume levels but my NS-1000,s are fairly efficient I believe 94 db so I don't need a lot of power to be extremely loud.
gni
I am running in my two ESP P101,s 800VA 50-0-50 Antek and Avel-lundberg toroidal xformers. They do not have even a hint of heat even operating for several hours at extremely loud volume levels but my NS-1000,s are fairly efficient I believe 94 db so I don't need a lot of power to be extremely loud.
yamaha
Hi,
Thanks. Partstore. Great shop. Unfortunately they do not have any parts for yamaha c- series preamps. Maybe one of cx series preamps has similar pots. That may deserve further investigation. Anyway, browsing through virtual shelves I found pioneer rt-909 recording head I need.
I have my power amp four toroids in a separate box. High power unregulated PS transformers run power cables with power plugs, while small transformers for regulated PS are connected to xlr sockets and connected using power cords with xlr plugs with power amps. It does not look as tidy as a multi conductor cable connection would look like but serves the purpose and cables have thick conductors.
Kerosine is a not a bad initial cleaner for pots but not all pots can be treated with kerosine. Alcohol washes off kerosine treated dirt and pot track is ready for further treatment with deoxidants (I use deoxit) and pot cleaners-lubricants.
If a pot is more worn off polishing of its track may help but most new pots can not be treated this way. It works well on old carbon pots with thick tracks.
Wife problem is as old as humanity. I have similar experiences even though my wife is a structural engineer. Anyway, I had recently an intersting conversation with a female doctor, who happens to be my colleague, on a topic of women.
She certainly is not a feminist darling as she openly says that 90% of women want to control everything and fear thretned by most things men like. A man's hobby to many women looks almost as suspicious as a lover. They want to be a centre of attention and men must be under their emotional control and they test that contrlo almost daily.
The other thing she says is that women are not inventive. The whole civilisation is built by a few talented men and without them we would still be aplike creatures. Women should inspire men - not burden them.
Maybe she has such views because she has a rich experience with career women coming to her when in their middle forties suddenly wanting to become mums. Problem that somehow they cannot get pregnant. Of course they have wrong husbands and everybody is guilty including laws of the nature. My collegue has also some recommndations how to manage to minimize man-woman relationship problems but it is not for this forum.
Back to audio. Caps in audio should be good quality and there should be few of these in a design. Our cap technologies are not so advanced yet. It is possible to test electrolytic caps simply mesuring their ESRI using high quality meters. One can also charge them and see how long it takes them to discharge. It is not that easy to find out whether a particular cap is Ok without removing it from a circuit if the problem is more complex and "transient" in nature. With old equipment it takes less time to replace all electros with new ones, which can be tested for major faults before being soldered in. The other thing is that old electros, if not expired, still work but not as well as new ones.
cheers,
Hi,
Thanks. Partstore. Great shop. Unfortunately they do not have any parts for yamaha c- series preamps. Maybe one of cx series preamps has similar pots. That may deserve further investigation. Anyway, browsing through virtual shelves I found pioneer rt-909 recording head I need.
I have my power amp four toroids in a separate box. High power unregulated PS transformers run power cables with power plugs, while small transformers for regulated PS are connected to xlr sockets and connected using power cords with xlr plugs with power amps. It does not look as tidy as a multi conductor cable connection would look like but serves the purpose and cables have thick conductors.
Kerosine is a not a bad initial cleaner for pots but not all pots can be treated with kerosine. Alcohol washes off kerosine treated dirt and pot track is ready for further treatment with deoxidants (I use deoxit) and pot cleaners-lubricants.
If a pot is more worn off polishing of its track may help but most new pots can not be treated this way. It works well on old carbon pots with thick tracks.
Wife problem is as old as humanity. I have similar experiences even though my wife is a structural engineer. Anyway, I had recently an intersting conversation with a female doctor, who happens to be my colleague, on a topic of women.
She certainly is not a feminist darling as she openly says that 90% of women want to control everything and fear thretned by most things men like. A man's hobby to many women looks almost as suspicious as a lover. They want to be a centre of attention and men must be under their emotional control and they test that contrlo almost daily.
The other thing she says is that women are not inventive. The whole civilisation is built by a few talented men and without them we would still be aplike creatures. Women should inspire men - not burden them.
Maybe she has such views because she has a rich experience with career women coming to her when in their middle forties suddenly wanting to become mums. Problem that somehow they cannot get pregnant. Of course they have wrong husbands and everybody is guilty including laws of the nature. My collegue has also some recommndations how to manage to minimize man-woman relationship problems but it is not for this forum.
Back to audio. Caps in audio should be good quality and there should be few of these in a design. Our cap technologies are not so advanced yet. It is possible to test electrolytic caps simply mesuring their ESRI using high quality meters. One can also charge them and see how long it takes them to discharge. It is not that easy to find out whether a particular cap is Ok without removing it from a circuit if the problem is more complex and "transient" in nature. With old equipment it takes less time to replace all electros with new ones, which can be tested for major faults before being soldered in. The other thing is that old electros, if not expired, still work but not as well as new ones.
cheers,
C-85 Continued Mods
I am going to move the transformer out of the
main C-85 box. It produces 60% of the heat
in the unit. . .Fan will be placed in its location.
I will use a 5-pin DIN for the two different
+/- supplies (+/- 40VAC CT and +/- 50VAC CT).
So. . . the two supplies will share the CT. . .
I need to measure if there is any voltage
difference between the two center taps. . .
if not, the 5-pin DIN will work great.
The main AC will still enter the C-85 as it does
but there will be a new jack (not sure what type
as of yet) to supply the 120VAC over to the
transformer box.
Connector ideas. . .originally I had 9 conductors
from the C-85 to the transformer box. . . down
to 7 if the mains enter the C-85 first. . .I wanted
all conductors in one cable. . .but I'm just not
jazzed about 120VAC and the lower voltage
taps sharing the same cable.
The final result will be a cooler running C-85
and extend it's life another few years.
Chris Browne
I am going to move the transformer out of the
main C-85 box. It produces 60% of the heat
in the unit. . .Fan will be placed in its location.
I will use a 5-pin DIN for the two different
+/- supplies (+/- 40VAC CT and +/- 50VAC CT).
So. . . the two supplies will share the CT. . .
I need to measure if there is any voltage
difference between the two center taps. . .
if not, the 5-pin DIN will work great.
The main AC will still enter the C-85 as it does
but there will be a new jack (not sure what type
as of yet) to supply the 120VAC over to the
transformer box.
Connector ideas. . .originally I had 9 conductors
from the C-85 to the transformer box. . . down
to 7 if the mains enter the C-85 first. . .I wanted
all conductors in one cable. . .but I'm just not
jazzed about 120VAC and the lower voltage
taps sharing the same cable.
The final result will be a cooler running C-85
and extend it's life another few years.
Chris Browne
c85
Hi Chris,
In c65 (as shown on circuit diagram) transformer winding are separate so I would provide separate connections for each section - no common centre tap. I used in the past 3 pin DIN sockets and plugs to provide AC from transformers to my linear preamp and equalizers and in a few other cases. They are OK. Now I'm using XLRs - connect better.
Why would you need mains AC in the preamp box? Transformer is out so mains AC is out. Immediate benefit are somewhat cleaner MC and MM. I do not know c85 circuit - is there anything else in the box needing mains?
In the end you would have two low voltage AC cables coming out of c85 instead of one mains AC cable. No mains in the preamp's box is a notable advantage.
cheers,
Hi Chris,
In c65 (as shown on circuit diagram) transformer winding are separate so I would provide separate connections for each section - no common centre tap. I used in the past 3 pin DIN sockets and plugs to provide AC from transformers to my linear preamp and equalizers and in a few other cases. They are OK. Now I'm using XLRs - connect better.
Why would you need mains AC in the preamp box? Transformer is out so mains AC is out. Immediate benefit are somewhat cleaner MC and MM. I do not know c85 circuit - is there anything else in the box needing mains?
In the end you would have two low voltage AC cables coming out of c85 instead of one mains AC cable. No mains in the preamp's box is a notable advantage.
cheers,
Transformer Placement
I am thinking I will mount the transformer
on the top on the C-85, near the back (allow room
for the electronic crossover) and keep the vent
holes clear for the new internal fan. . .which
will have a high speed and low speed setting
via the old voltage select switch.
That will allow me to direct connect the existing
wires from the secondary of the transformer
to the internal connections. I will keep room
clear incase I need top holes for bigger caps (taller).
I will take a pic of the mock up that I want.
Chris
I am thinking I will mount the transformer
on the top on the C-85, near the back (allow room
for the electronic crossover) and keep the vent
holes clear for the new internal fan. . .which
will have a high speed and low speed setting
via the old voltage select switch.
That will allow me to direct connect the existing
wires from the secondary of the transformer
to the internal connections. I will keep room
clear incase I need top holes for bigger caps (taller).
I will take a pic of the mock up that I want.
Chris
C-85 Transformer secondary
You were right(and so is the schematic)!
The transformer contains two individual secondaries.
There is no connection between the two center taps
or the other secondaries.
BUT
once connected to the two different PCB boards
the center taps become one connection! which makes
sense: the same 0V center tap = reduced voltage
potential = reduced noise. . .
SO
it seems it doesn't matter when the center taps connect
since they will connect on the PCBs.
See what you think.
Chris
You were right(and so is the schematic)!
The transformer contains two individual secondaries.
There is no connection between the two center taps
or the other secondaries.
BUT
once connected to the two different PCB boards
the center taps become one connection! which makes
sense: the same 0V center tap = reduced voltage
potential = reduced noise. . .
SO
it seems it doesn't matter when the center taps connect
since they will connect on the PCBs.
See what you think.
Chris
c85
Hi Chris,
Centre taps should go where they go. Some separation of board grounds is necessary. Of course all grounds must connect together at some point but until then separation of circuits is often necessary.
Puting transformers on top of the box is OK but I'd put them in a separate box if I was to use phono inputs - especially MC. Otherwise it does not matter much.
cheers,
Hi Chris,
Centre taps should go where they go. Some separation of board grounds is necessary. Of course all grounds must connect together at some point but until then separation of circuits is often necessary.
Puting transformers on top of the box is OK but I'd put them in a separate box if I was to use phono inputs - especially MC. Otherwise it does not matter much.
cheers,
I was a little worried about that. . .the transformer sitting
on top(back left) might put it closer to the MC/MM circuit(back right).
The lack of good boxes or cages is extreme. Been taking a break
to fix my Canon Elan II door latch (3 latchs for $14!) verses ($80 by repair shop); also had to fix friends inkjet printer that the vacuum
hose kept slipping off. . .finished up tape->DVDs!
Free to work on my projects! ! ! !
I thought it would be interesting to mount the transformer on
a piece of cultured marble (drill holes and bolt down). Since the
actually transformer is gunked into a case. . .the case is insulated
from the transformer. . .save to have exposed to human contact.
I'll send the pictures in next.
Chris
on top(back left) might put it closer to the MC/MM circuit(back right).
The lack of good boxes or cages is extreme. Been taking a break
to fix my Canon Elan II door latch (3 latchs for $14!) verses ($80 by repair shop); also had to fix friends inkjet printer that the vacuum
hose kept slipping off. . .finished up tape->DVDs!
Free to work on my projects! ! ! !
I thought it would be interesting to mount the transformer on
a piece of cultured marble (drill holes and bolt down). Since the
actually transformer is gunked into a case. . .the case is insulated
from the transformer. . .save to have exposed to human contact.
I'll send the pictures in next.
Chris
Transformer Connections Complete
At last. . .the C-85 is almost done!
Transformer is on the top. . .just need some bolts.
The wires inside took up more room than I thought. . . might
make it difficult to mount the fan. . . needed enough wire to
pull off the top and service the interior. One problem of mounting
the transformer on top.
With the electronic crossover on top. . .the transformer is just
shorter that the x-over unit. . . .upload pictures next.
Tight fit for RCAs around the transformer.
I'll run it all night to see where the heat build ups are.
Pictures soon.
Chris
At last. . .the C-85 is almost done!
Transformer is on the top. . .just need some bolts.
The wires inside took up more room than I thought. . . might
make it difficult to mount the fan. . . needed enough wire to
pull off the top and service the interior. One problem of mounting
the transformer on top.
With the electronic crossover on top. . .the transformer is just
shorter that the x-over unit. . . .upload pictures next.
Tight fit for RCAs around the transformer.
I'll run it all night to see where the heat build ups are.
Pictures soon.
Chris
C-85 Mods Done
The Yamaha C-85 Preamp modifications are done!
What a difference. . .with the fan inside and the transformer mounted
on top, heat is not a factor. . .since the fan exit is next to the
transformer it stays cooler by many degrees. . .it is warm but not
so hot as to make you want to remove your hand. The fan is
switched on or off by the old voltage selector switch. The outlets
are now removed (there wasn't enough room for them inside with
the fan and the wires from the transformer to the terminal block.
Now I need several more outlets for connecting equipment. The
electronic crossover has one. . .but still need another for the fan
transformer. . .looking for smaller transformer (9VDC 200 mA).
The current one is big and maybe more than I need. . .
Pictures coming soon. . .
The Yamaha C-85 Preamp modifications are done!
What a difference. . .with the fan inside and the transformer mounted
on top, heat is not a factor. . .since the fan exit is next to the
transformer it stays cooler by many degrees. . .it is warm but not
so hot as to make you want to remove your hand. The fan is
switched on or off by the old voltage selector switch. The outlets
are now removed (there wasn't enough room for them inside with
the fan and the wires from the transformer to the terminal block.
Now I need several more outlets for connecting equipment. The
electronic crossover has one. . .but still need another for the fan
transformer. . .looking for smaller transformer (9VDC 200 mA).
The current one is big and maybe more than I need. . .
Pictures coming soon. . .
Yamaha C-85 Mods Finished. . .
Making modifications to production level electronics can be
something of a challenge. This will be my final posting unless I
get the replacement caps sometime before the Social Security
goes belly-up.
Take a look at the final photo. Fan is in place of transformer; the
transformer is mounted on top. Extension wires were necessary
since the original leads were too short. The A/C outlets were
removed to make room for the extra leads; it may be better not
running A/C current from all the sources through the sockets
mounted on the preamp. It won't matter anyway. . .the sockets
are gone.
The only remaining problem is the wall-wart for the fan. . .I would
still like to find a 200mA 9VAC transformer and use a diode to run
the fan; that would reduce the size of the wall-wart which is
currently about 7.5cm x 5.5cm x 4cm. I have a walkie-talkie charger
that uses a 9VAC 200mA wall-wart that is only 6cm x 4cm x 2.5cm!
It is only a 12VDC fan and only needs 1/2 wave DC to function. I
could probably use a 7.5 VAC wall-wart and reduce the size further.
I would like to mount it on the back of the C-85 as if it were
plugged in. . . but mounted with bolts and wired into the AC mains.
Thank you all who helped. I hope this thread heaps somebody
on a similar project in the future. Making mods to existing products
is a great way to learn how to build electronic equipment.
Chris Browne
Making modifications to production level electronics can be
something of a challenge. This will be my final posting unless I
get the replacement caps sometime before the Social Security
goes belly-up.
Take a look at the final photo. Fan is in place of transformer; the
transformer is mounted on top. Extension wires were necessary
since the original leads were too short. The A/C outlets were
removed to make room for the extra leads; it may be better not
running A/C current from all the sources through the sockets
mounted on the preamp. It won't matter anyway. . .the sockets
are gone.
The only remaining problem is the wall-wart for the fan. . .I would
still like to find a 200mA 9VAC transformer and use a diode to run
the fan; that would reduce the size of the wall-wart which is
currently about 7.5cm x 5.5cm x 4cm. I have a walkie-talkie charger
that uses a 9VAC 200mA wall-wart that is only 6cm x 4cm x 2.5cm!
It is only a 12VDC fan and only needs 1/2 wave DC to function. I
could probably use a 7.5 VAC wall-wart and reduce the size further.
I would like to mount it on the back of the C-85 as if it were
plugged in. . . but mounted with bolts and wired into the AC mains.
Thank you all who helped. I hope this thread heaps somebody
on a similar project in the future. Making mods to existing products
is a great way to learn how to build electronic equipment.
Chris Browne
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