My PL700B by Marco
- Thread starter marcok
- Start date
I have some questions about PL 700B transistors , because after a more
in depth diagnosis these transistor are K.O. (one channel only )
- 2N 1304 ( is 2N 440 A a good replacement ?)
- 2N 1305 ( already found )
- Rca 40327 ( is 2N 3440 a good replacement ? )
- 2N 3403 ( is it possible to re-use the heatsink ? )
- RCA 410 ( is MJ 1800 a good replacemement ? )
For power transistors no problem , because I have a complete set ( 20 )
of XPL 909 marked with blue ink like original ( 5 K.O )
Anyway no problem to find everything in ebay.com
Replacement transistors are available in Italy and UK .
Thank you in advance and ciao
Marco
P.S: a little surprise : Phase Linear mounted a 10 A fuse instead of 5A on AC mains .
Unbelievable .
in depth diagnosis these transistor are K.O. (one channel only )
- 2N 1304 ( is 2N 440 A a good replacement ?)
- 2N 1305 ( already found )
- Rca 40327 ( is 2N 3440 a good replacement ? )
- 2N 3403 ( is it possible to re-use the heatsink ? )
- RCA 410 ( is MJ 1800 a good replacemement ? )
For power transistors no problem , because I have a complete set ( 20 )
of XPL 909 marked with blue ink like original ( 5 K.O )
Anyway no problem to find everything in ebay.com
Replacement transistors are available in Italy and UK .
Thank you in advance and ciao
Marco
P.S: a little surprise : Phase Linear mounted a 10 A fuse instead of 5A on AC mains .
Unbelievable .
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Marco,
The 2N3440 will work as a replacement for the 40327.
Other people on this forum have been re-using the 2N3403 heat-sink.
Although Phase Linear used the MJ1800's as driver transistors for a short period of time, I do not know how "good" or reliable it was and why they stopped using it.
NOTE: There is a fellow on ebay in the U.S. selling RCA410's for less than $2.50 each.
https://www.ebay.it/itm/RCA410-RCA-...578831?hash=item51d6a6604f:g:gaEAAOSwDNdV3kYX
Since you are in Italy and the line voltage should be around 230V, I would expect the AC (line supply) fuses to be 5A not 10A (for 120V use).
Ed
The 2N3440 will work as a replacement for the 40327.
Other people on this forum have been re-using the 2N3403 heat-sink.
Although Phase Linear used the MJ1800's as driver transistors for a short period of time, I do not know how "good" or reliable it was and why they stopped using it.
NOTE: There is a fellow on ebay in the U.S. selling RCA410's for less than $2.50 each.
https://www.ebay.it/itm/RCA410-RCA-...578831?hash=item51d6a6604f:g:gaEAAOSwDNdV3kYX
Since you are in Italy and the line voltage should be around 230V, I would expect the AC (line supply) fuses to be 5A not 10A (for 120V use).
Ed
Possible , because everything is possible ,
but I know the history of this unit .
40 years ago my hifi guru sold it to the previous owner factory made .
The reason of this fault is that this guy lately used this unit in the
bathroom every morning for 10 minutes during shaving .
Humidity and condensation and after obviously smoke !
My hifi guru worked in a shop that was the official retailer for Milan zone
for PL , Altec, Klipsch and other makes and furthermore
the lab of this shop was the PL official repair center for Italy .
Any way they are things that happen .
Now I request infos about transistors to do the best choice .
Ciao
Marco
but I know the history of this unit .
40 years ago my hifi guru sold it to the previous owner factory made .
The reason of this fault is that this guy lately used this unit in the
bathroom every morning for 10 minutes during shaving .
Humidity and condensation and after obviously smoke !
My hifi guru worked in a shop that was the official retailer for Milan zone
for PL , Altec, Klipsch and other makes and furthermore
the lab of this shop was the PL official repair center for Italy .
Any way they are things that happen .
Now I request infos about transistors to do the best choice .
Ciao
Marco
I don't know how they measure the delay between two cars in case of safety car .
There is a sensor on the front wheel ( I don't remenber if left or right ) and the measurement has made
between two dedicated rows along the circuit .Why not on the rear wheel ?
Simple there is the traction control .
Last year there was the Twing to "improve " the aerodynamics . It looked like a VHF dipole .
I have no words . Too much SW .
Fortunately there are " toys" just like PL 700B equipped with germanium transinstor !
No SW , no uP but it sounds !
Ciao
Marco
There is a sensor on the front wheel ( I don't remenber if left or right ) and the measurement has made
between two dedicated rows along the circuit .Why not on the rear wheel ?
Simple there is the traction control .
Last year there was the Twing to "improve " the aerodynamics . It looked like a VHF dipole .
I have no words . Too much SW .
Fortunately there are " toys" just like PL 700B equipped with germanium transinstor !
No SW , no uP but it sounds !
Ciao
Marco
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Just finished to restore front panel :
- removed little scratches on alu front panel with steel wool # 0000 ( generally used to restore old forniture )
- cleaned front panel with ammonia
- retouched plastic mask with with flat black on the the rear side by a microbrush
-replace blue film with " gel " film like original
-cleaned VUs ( inside / outside ) with lcd screen cleaner
-spray painted VU frames .
-spray painted top cover with alu primer and matt black
-ordered in UK 2N 1304 , 2N 1305 and 2N 3403 ( brand TI )
Now I have to wait for 1 week to receive transistors .
Ciao
Marco
PS : It looks like new .
- removed little scratches on alu front panel with steel wool # 0000 ( generally used to restore old forniture )
- cleaned front panel with ammonia
- retouched plastic mask with with flat black on the the rear side by a microbrush
-replace blue film with " gel " film like original
-cleaned VUs ( inside / outside ) with lcd screen cleaner
-spray painted VU frames .
-spray painted top cover with alu primer and matt black
-ordered in UK 2N 1304 , 2N 1305 and 2N 3403 ( brand TI )
Now I have to wait for 1 week to receive transistors .
Ciao
Marco
PS : It looks like new .
Thank you !
But many thanks to my hi fi guru for electrical repair and to
his son in law for polishing handles and knobs .
Curiosities found during the job :
-Caps size looks different
-Handles are made in zamak and not in alu
-Knobs screws are used as a reference point for level pots ( from You Tube )
So decals are useless .
True ?
Ciao
Marco
But many thanks to my hi fi guru for electrical repair and to
his son in law for polishing handles and knobs .
Curiosities found during the job :
-Caps size looks different
-Handles are made in zamak and not in alu
-Knobs screws are used as a reference point for level pots ( from You Tube )
So decals are useless .
True ?
Ciao
Marco
