yaputya
Guest
Wed Dec 28, 2011 1:24 am
I'm looking for the circuit and ETI article for the mini-amp ETI453 from
ETI April 1980 (also published (I think) as the HE105.)
I've got a couple of PCBs but have long ago thrown out the ETI mag.
It seems to use an op-amp, three small-signal transistors and two power
transistors, from the pcb pattern.
Any old-timers out there who can help shed any light?
F Murtz
Guest
Wed Dec 28, 2011 1:43 am
yaputya wrote:
Quote:
I'm looking for the circuit and ETI article for the mini-amp ETI453 from
ETI April 1980 (also published (I think) as the HE105.)
I've got a couple of PCBs but have long ago thrown out the ETI mag.
It seems to use an op-amp, three small-signal transistors and two power
transistors, from the pcb pattern.
Any old-timers out there who can help shed any light?
What I did after some helpful info from Phil (and some abuse) about
which issue, was to join the big library in sydney (they keep copies )
and copy article.
Phil Allison
Guest
Wed Dec 28, 2011 3:23 am
"yaputya"
Quote:
I'm looking for the circuit and ETI article for the mini-amp ETI453 from
ETI April 1980 (also published (I think) as the HE105.)
I've got a couple of PCBs but have long ago thrown out the ETI mag.
It seems to use an op-amp, three small-signal transistors and two power
transistors, from the pcb pattern.
Any old-timers out there who can help shed any light?
** Is the PCB designed to accept PSU components and two TO3 devices on
heatsinks like this:
http://media.digikey.com/photos/Aavid%20Thermalloy%20Photos/50150&501603B00000.jpg
.... Phil
kreed
Guest
Wed Dec 28, 2011 5:23 am
On Dec 28, 10:24 am, "yaputya" <yaputya.leftle...@gmail.com> wrote:
Quote:
I'm looking for the circuit and ETI article for the mini-amp ETI453 from
ETI April 1980 (also published (I think) as the HE105.)
I've got a couple of PCBs but have long ago thrown out the ETI mag.
It seems to use an op-amp, three small-signal transistors and two power
transistors, from the pcb pattern.
Any old-timers out there who can help shed any light?
I would still have it around here somewhere
Tom
Guest
Wed Dec 28, 2011 8:17 am
On 28/12/2011 10:24 AM, yaputya wrote:
Quote:
I'm looking for the circuit and ETI article for the mini-amp ETI453 from
ETI April 1980 (also published (I think) as the HE105.)
I've got a couple of PCBs but have long ago thrown out the ETI mag.
It seems to use an op-amp, three small-signal transistors and two power
transistors, from the pcb pattern.
Any old-timers out there who can help shed any light?
I got old "Audio Projects from ETI" mag with this amp, it uses LM301, BC557, BC639/BC640 and TIP31/32 for output stage. If you provide working email I can scan and send you the article.
Tom
Phil Allison
Guest
Wed Dec 28, 2011 12:29 pm
"Tom"
Quote:
yaputya wrote:
I'm looking for the circuit and ETI article for the mini-amp ETI453 from
ETI April 1980 (also published (I think) as the HE105.)
I've got a couple of PCBs but have long ago thrown out the ETI mag.
It seems to use an op-amp, three small-signal transistors and two power
transistors, from the pcb pattern.
Any old-timers out there who can help shed any light?
I got old "Audio Projects from ETI" mag with this amp, it uses LM301,
BC557, BC639/BC640 and TIP31/32 for output stage.
** That is the same PCB I used a few times back in the early 80s - but
modified it so TO3s (ie 2N3055 and MJ2955 ) would fit in place of the
TO220s.
Configured it as a Wien bridge, self oscillating, sine wave power amplifier
using a 6.3 volt bulb for amplitude stability. The output drove a 15 watt
valve output transformer ( A&R ) in reverse to produce a 240V, 50 Hz sine
wave with adjustable frequency over a narrow range.
The purpose was fine pitch tuning for a synchronous turntable.
Was published in the design ideas pages of ETI in the early 80s.
..... Phil
yaputya
Guest
Wed Dec 28, 2011 11:03 pm
"Phil Allison" <phil_a_at_tpg.com.au> wrote in message news:9lvcsqF11eU1_at_mid.individual.net...
Quote:
"yaputya"
I'm looking for the circuit and ETI article for the mini-amp ETI453 from
ETI April 1980 (also published (I think) as the HE105.)
I've got a couple of PCBs but have long ago thrown out the ETI mag.
It seems to use an op-amp, three small-signal transistors and two power
transistors, from the pcb pattern.
Any old-timers out there who can help shed any light?
** Is the PCB designed to accept PSU components and two TO3 devices on heatsinks like this:
http://media.digikey.com/photos/Aavid%20Thermalloy%20Photos/50150&501603B00000.jpg
... Phil
No, it doesn't seem to have rectifiers etc. and has 6 pads near the edge
of the pcb that would take 2 TO220 transistors, not TO3s.
PCB is 83mm x 50mm, coded ETI453.
yaputya
Guest
Wed Dec 28, 2011 11:08 pm
"Tom" <tom_at_no.spam.invalid> wrote in message news:jdefpo$ebo$1_at_dont-email.me...
Quote:
On 28/12/2011 10:24 AM, yaputya wrote:
I'm looking for the circuit and ETI article for the mini-amp ETI453 from
ETI April 1980 (also published (I think) as the HE105.)
I've got a couple of PCBs but have long ago thrown out the ETI mag.
It seems to use an op-amp, three small-signal transistors and two power
transistors, from the pcb pattern.
Any old-timers out there who can help shed any light?
I got old "Audio Projects from ETI" mag with this amp, it uses LM301, BC557, BC639/BC640 and TIP31/32 for output stage. If you
provide working email I can scan and send you the article.
Tom
Thanks, I use a working email for ngs so just reply to sender.
yaputya
Guest
Wed Dec 28, 2011 11:11 pm
"Phil Allison" <phil_a_at_tpg.com.au> wrote in message news:9m0cseFkh6U1_at_mid.individual.net...
Quote:
"Tom"
yaputya wrote:
I'm looking for the circuit and ETI article for the mini-amp ETI453 from
ETI April 1980 (also published (I think) as the HE105.)
I've got a couple of PCBs but have long ago thrown out the ETI mag.
It seems to use an op-amp, three small-signal transistors and two power
transistors, from the pcb pattern.
Any old-timers out there who can help shed any light?
I got old "Audio Projects from ETI" mag with this amp, it uses LM301, BC557, BC639/BC640 and TIP31/32 for output stage.
** That is the same PCB I used a few times back in the early 80s - but modified it so TO3s (ie 2N3055 and MJ2955 ) would fit in
place of the TO220s.
Configured it as a Wien bridge, self oscillating, sine wave power amplifier using a 6.3 volt bulb for amplitude stability. The
output drove a 15 watt valve output transformer ( A&R ) in reverse to produce a 240V, 50 Hz sine wave with adjustable frequency
over a narrow range.
The purpose was fine pitch tuning for a synchronous turntable.
Was published in the design ideas pages of ETI in the early 80s.
.... Phil
That is interesting, could you scan your circuit and post it somewhere
(or just email it to me).
Phil Allison
Guest
Wed Dec 28, 2011 11:32 pm
"yaputya"
Quote:
"Phil Allison"
** That is the same PCB I used a few times back in the early 80s - but
modified it so TO3s (ie 2N3055 and MJ2955 ) >> would fit in place of
the TO220s.
Configured it as a Wien bridge, self oscillating, sine wave power
amplifier using a 6.3 volt bulb for amplitude stability. >> The output
drove a 15 watt valve output transformer ( A&R ) in reverse to produce a
240V, 50 Hz sine wave with adjustable frequency over a narrow range.
The purpose was fine pitch tuning for a synchronous turntable.
Was published in the design ideas pages of ETI in the early 80s.
That is interesting, could you scan your circuit and post it somewhere
** After 30 years, I no longer have a copy.
Silicon Chip magazine have back issues of most EA and ETI mags and will
copy articles for a small fee.
.... Phil
