Good Day Everyone
Has anyone here build the A.R Bailey amplifier from Daan Jacobs from the early 1970's.
i have started with the rebuild of this amp that i got from my father but i only have the diag. but there is no information on the Trifiliar Transformer on the diag. i am looking at updating the components on the am and this is my 1st stumbling block.
This am uses TIP2955 output transistor's.
Sorry i am a noob with electronics i just know enough to not kill my self.
All help will be appreciated.
Thanks.
Has anyone here build the A.R Bailey amplifier from Daan Jacobs from the early 1970's.
i have started with the rebuild of this amp that i got from my father but i only have the diag. but there is no information on the Trifiliar Transformer on the diag. i am looking at updating the components on the am and this is my 1st stumbling block.
This am uses TIP2955 output transistor's.
Sorry i am a noob with electronics i just know enough to not kill my self.
All help will be appreciated.
Thanks.
I have two off 20 watt Baileys
the first one is an original powertran kit the second a fabulous Clone built to a very high standard ! This was obtained at a high cost from the well known auction site it really is a work of art
I remember seeing the schematic to this in I a1964 i think copy of hifi news annual
Arthur Bailey great designer
Trev
the first one is an original powertran kit the second a fabulous Clone built to a very high standard ! This was obtained at a high cost from the well known auction site it really is a work of art
I remember seeing the schematic to this in I a1964 i think copy of hifi news annual
Arthur Bailey great designer
Trev
Here is the diag for the amp i am currently working on
but i dont see any information on the transformer on the amp so i am not sure what to go and look for as a replacement on it.
but i dont see any information on the transformer on the amp so i am not sure what to go and look for as a replacement on it.
Thanks for your schematic that you have attached I can see it has not been fitted with the drive limiting network of the original Also the original used Germanium output devices ! Bailey did do a second option that used Silicon NPN output devices
My version has the original Germanium devices
This amplifier was never really a commercial success I never did see a Radford version
Arthur bailey within a few years 4 came up with his fully complimentary version SCA30 that was a success
The nearest commercial implementation would be the Rogers Ravensbrook that adopted a trifilar wound driver transformer ( nice little amp) but was single supply so had an output capacitor
I am so pleased to find some one else out their that still likes this topology it has many advantages but the cost of the driver tx is against them these days
Are you winding your own ?
Trev
My version has the original Germanium devices
This amplifier was never really a commercial success I never did see a Radford version
Arthur bailey within a few years 4 came up with his fully complimentary version SCA30 that was a success
The nearest commercial implementation would be the Rogers Ravensbrook that adopted a trifilar wound driver transformer ( nice little amp) but was single supply so had an output capacitor
I am so pleased to find some one else out their that still likes this topology it has many advantages but the cost of the driver tx is against them these days
Are you winding your own ?
Trev
Thanks this was my 1st amp about 30 years ago i got from my dad.
Daan Jacobs use to sell this amp + preamp as kits in the early 1970, and from what i could find is that no so may bought and build these amps and preamps.
for the transformer i am looking at a company that winds transformers to make 2 of them for me but this is were my 1st problem comes in, i have no information on this triformer so i am not sure what to tell them to make for me.
William.
Daan Jacobs use to sell this amp + preamp as kits in the early 1970, and from what i could find is that no so may bought and build these amps and preamps.
for the transformer i am looking at a company that winds transformers to make 2 of them for me but this is were my 1st problem comes in, i have no information on this triformer so i am not sure what to tell them to make for me.
William.
Hold on I have just gone over the schematic the driver -predriver are both NPN in the original the pre driver was NPN and the driver was PNP t03 germanium
The disadvantage with the NPN NPN arrangement is possible lack of drive on the positive
part of the cycle I overcame this on my version by splitting the collector load of the pre diver and bootstrapping from the emitter of the driver much more linear
Trev
The disadvantage with the NPN NPN arrangement is possible lack of drive on the positive
part of the cycle I overcame this on my version by splitting the collector load of the pre diver and bootstrapping from the emitter of the driver much more linear
Trev
There are details re the transformer and that's where the difficulties lie
I will try and down load the information for you it's very simple but you do need the core formers and wire I have made my own but that would be twenty years ago
Trev
I will try and down load the information for you it's very simple but you do need the core formers and wire I have made my own but that would be twenty years ago
Trev
bailey amp
Arthur Bailey "High-Performance Transistor Amplifier" (20W) published Wireless World Nov, Dec 1966, p542
you will find the article on the american wireless world archive
Trev
Arthur Bailey "High-Performance Transistor Amplifier" (20W) published Wireless World Nov, Dec 1966, p542
you will find the article on the american wireless world archive
Trev
1st WoW what a web site, i am not sure why i haven't come across it before what a lot of information is stored in there
Thanks a MIL. Trev
2nd so i got the information on the trifilar thanks that seems easy enough to make. In your opinion the 500R 9W resistors would it make a big difference if it was replaced with 470R 9/10W resistors, and also the 1R i see the author says it is not advisable to use a wire-wind resistor for this amplifier do you perhaps know how this is resistor is made (sorry i am really not sure about this zig zag resistor)
also thanks for the information
""The disadvantage with the NPN NPN arrangement is possible lack of drive on the positive
part of the cycle I overcame this on my version by splitting the collector load of the pre diver and bootstrapping from the emitter of the driver much more linear"
this is something i will look into as modifications but i think 1st i need to just get it up and running, as soon as the amp is done i will have to start with the Bailey Pre-Amp
https://worldradiohistory.com/UK/Wireless-World/60s/Wireless-World-1966-12.pdf
but i suspect i will have issue obtaining the components but that headache will have to wait for now.
Thanks a MIL. Trev
2nd so i got the information on the trifilar thanks that seems easy enough to make. In your opinion the 500R 9W resistors would it make a big difference if it was replaced with 470R 9/10W resistors, and also the 1R i see the author says it is not advisable to use a wire-wind resistor for this amplifier do you perhaps know how this is resistor is made (sorry i am really not sure about this zig zag resistor)
also thanks for the information
""The disadvantage with the NPN NPN arrangement is possible lack of drive on the positive
part of the cycle I overcame this on my version by splitting the collector load of the pre diver and bootstrapping from the emitter of the driver much more linear"
this is something i will look into as modifications but i think 1st i need to just get it up and running, as soon as the amp is done i will have to start with the Bailey Pre-Amp
https://worldradiohistory.com/UK/Wireless-World/60s/Wireless-World-1966-12.pdf
but i suspect i will have issue obtaining the components but that headache will have to wait for now.
So pleased to be of help ! If you change the 500 to 470 the bias current will increase
you need to lower the bottom bias resistor by the same amount The emitter resistors need to be non inductive that's all
All devices can be obtained easily nothing special by todays standards
Trev
you need to lower the bottom bias resistor by the same amount The emitter resistors need to be non inductive that's all
All devices can be obtained easily nothing special by todays standards
Trev
Hi,
I have built a RS-TA20 and RS-TA90 from a kit in the early 1980's with a friend that was '"electronically minded""
I want to revive the system but unfortunately I don't have any of the manuals and the wiring to all the different components (tuner, disk player, tape recorder etc) went missing years ago.
Where can I find these manuals or point me to someone that can assist me
I am not a electronic Geek/Boffin
Hannes
I have built a RS-TA20 and RS-TA90 from a kit in the early 1980's with a friend that was '"electronically minded""
I want to revive the system but unfortunately I don't have any of the manuals and the wiring to all the different components (tuner, disk player, tape recorder etc) went missing years ago.
Where can I find these manuals or point me to someone that can assist me
I am not a electronic Geek/Boffin
Hannes
Hi HannesMain
The RS-TA90 is a 100W JLW Amp Design and the RS-TA20 was a Bailey Pre-Amp was this bought at Daan Jacobs shop in JHB?
Hi All
i have a question in regards to the Emitter resistors 1ohm.
i checked how to make them as a commercial resistor will not work that well due to induction forming, but can someone please assist me to check how long the wire will need to be to get the recommended 1ohm over it, i have the following thickness insolated copper wires at hand
0.17mm
0.20mm
0.28mm
0.63mm
1.00mm
i suspect the .63 and the 1mm wire is way to think to use for this.
Thanks
William
i have a question in regards to the Emitter resistors 1ohm.
i checked how to make them as a commercial resistor will not work that well due to induction forming, but can someone please assist me to check how long the wire will need to be to get the recommended 1ohm over it, i have the following thickness insolated copper wires at hand
0.17mm
0.20mm
0.28mm
0.63mm
1.00mm
i suspect the .63 and the 1mm wire is way to think to use for this.
Thanks
William
I would not use copper at all use either constantan or nichrome wire
better still just purchase a 1 ohm resistor I am 100 % sure it will be ok
Trev
better still just purchase a 1 ohm resistor I am 100 % sure it will be ok
Trev
Thanks Trev
i replaced the wire resistors years ago with 1ohm resistor's but i was not sure if that would be the best option if i read the article but then again i am no electronic head but for now i will leave the resistors in as is. Thanks i am now off to go and take out output transistors to test them and then I can test the amp before i hook up my speakers.
Thanks for the help.
William
i replaced the wire resistors years ago with 1ohm resistor's but i was not sure if that would be the best option if i read the article but then again i am no electronic head but for now i will leave the resistors in as is. Thanks i am now off to go and take out output transistors to test them and then I can test the amp before i hook up my speakers.
Thanks for the help.
William