MIG pro amplifiers ( MIG = made in greece ) existed before chinese war many clubs used them some of them were really products of excellent quality ( considering that made arround 1980-1990 ) but some others was a complete catastrophe ....
for the fun of it i ll give some pictures of a greek made catastrophe and may be some time in the feature i will be able to present some good ones
in the pictures please notice reasons for catastrophe and all the classical mistakes made
the circuit is something like the ET 480 or ETI 480 dont really remember that actually drives a pair of BD 139-140 for pre drivers that drive a pair of MJ15024-25 for drivers that drive 10 ( ten ) outputs MJ15024-25 ( that is a triple darligton ??? )
beyond a typical I limmiter no other protection
outputs are "wired" with any available cable
no soft start or output relay
5pair of MJ15024-025 work with only 2x10.000 mfd
inductor dumper is located inside the inductor
there is no "rail" to supply outputs
1R10W emmiter resistors ( ???? ) just to be on the safe side
no balanced input
ground is the box and thats it !!!
and of course vbe multiplier is located on the pcb and has no physical contact with the pcb
ventilator is too small and only injects fresh air inside the box but no where to come out ( no ventilation chanel )
now let us be kinda of fair ....this amplifier is constructed by a company that normally produces 100V amplifiers by that ... standards of quality for 100V speakers and installations ar fairly low it is not real hifi ... so they used the same pcb for a PA amplifier while using 10 pairs of MJ 15024-25 to produce arround 250 CR@@PY WATTS ... that of course is a waist of parts ...but its done to keep it on the safe side probably together with 1R10W emmiter resistors
of course if this amplifier is pushed to the edge will fail since the right side output transitor has the longest cable its too far away from the ventilator and the temperature is not controlled by anything
still ...this amplifier was never expected to work on the edge since it was originally designed for hoteling IE as a PA amplifier to work inside a hotel for a small party or a small bussines meeting ... made arround 1985 ...still working ...
amazing
enjoy the pictures
for the fun of it i ll give some pictures of a greek made catastrophe and may be some time in the feature i will be able to present some good ones
in the pictures please notice reasons for catastrophe and all the classical mistakes made
the circuit is something like the ET 480 or ETI 480 dont really remember that actually drives a pair of BD 139-140 for pre drivers that drive a pair of MJ15024-25 for drivers that drive 10 ( ten ) outputs MJ15024-25 ( that is a triple darligton ??? )
beyond a typical I limmiter no other protection
outputs are "wired" with any available cable
no soft start or output relay
5pair of MJ15024-025 work with only 2x10.000 mfd
inductor dumper is located inside the inductor
there is no "rail" to supply outputs
1R10W emmiter resistors ( ???? ) just to be on the safe side
no balanced input
ground is the box and thats it !!!
and of course vbe multiplier is located on the pcb and has no physical contact with the pcb
ventilator is too small and only injects fresh air inside the box but no where to come out ( no ventilation chanel )
now let us be kinda of fair ....this amplifier is constructed by a company that normally produces 100V amplifiers by that ... standards of quality for 100V speakers and installations ar fairly low it is not real hifi ... so they used the same pcb for a PA amplifier while using 10 pairs of MJ 15024-25 to produce arround 250 CR@@PY WATTS ... that of course is a waist of parts ...but its done to keep it on the safe side probably together with 1R10W emmiter resistors
of course if this amplifier is pushed to the edge will fail since the right side output transitor has the longest cable its too far away from the ventilator and the temperature is not controlled by anything
still ...this amplifier was never expected to work on the edge since it was originally designed for hoteling IE as a PA amplifier to work inside a hotel for a small party or a small bussines meeting ... made arround 1985 ...still working ...
amazing
enjoy the pictures
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true true ... you also may as well remember the japanese makes of the time that had non of these problems i think that at the time you could also find very nice either comercial or DIY machines ,,,
( is good also to remember that at the times greece was politically unstable had some oscillation ha ha ha ha resulting that till 1975 USA didnt supply much of technology here Just to be on the safe side )
( is good also to remember that at the times greece was politically unstable had some oscillation ha ha ha ha resulting that till 1975 USA didnt supply much of technology here Just to be on the safe side )
9th Greek Tragedy
Pardon my attemp at humor in advance. Most US academic track eighth grade students purchase and read a book called "Eight Great Greek Tragedies". Oedipus, Aeschelus etc. There are hundreds of these paperbacks in the charity resale shops. Now you have written the ninth Great Greek Tragedy. Sakis"s ninth!
Pardon my attemp at humor in advance. Most US academic track eighth grade students purchase and read a book called "Eight Great Greek Tragedies". Oedipus, Aeschelus etc. There are hundreds of these paperbacks in the charity resale shops. Now you have written the ninth Great Greek Tragedy. Sakis"s ninth!
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Looks like many generic SS amps from the early 1980's. Bad? Maybe, but then again we're likely spoiled by modern manufacturing standards.
If you open up any SS instrument amp from that era, chance is it looks way worse and quotes the same output power ratings with lesser heatsinking, fewer output transistors, smaller transformer and no fan at all.
Oh and...
If you open up any SS instrument amp from that era, chance is it looks way worse and quotes the same output power ratings with lesser heatsinking, fewer output transistors, smaller transformer and no fan at all.
Oh and...
pretty much sums it up.
more or less you are correct ...but ..dont forget this is the 1980....and this is a bad manufacturer...at the time there used to be a lot better ones
Back in the days of Iron Curtain and sleeping China, when ''Made in Greece'' was not only a comedy flick title, import taxes were high, and there were some small PA local firms about, indeed. 100V commercial sound installer spin off ventures mainly. I do remember maybe an STT brand with nice chassis and Tx, though its engineering looked weird at least, if I recall correctly. Do you have any more brand and model samples from that era, and which one was competent enough in retrospect? The ''catastrophe'' you showed, did something remarkable though...still plays, yes?
yeap it still plays and may of these amplifier are still working in lofi applications ... in a few words the particular amps actaually served the perpus and the reason they were made for .... i think that is a good target to achieve
For the record i am placing a few words about the other amplifiers MIG at the time and some of them still going strong ....
in the 100V area
Dublex started with tube amplifiers mooved to transitors and as a sub constructor provided amplifiers for other brand names like the first Audio Brain ...and as seen the above GTH
ALVA did allmost copycuts of Dublex full range of 2N3055 amplifiers with mixers and mic preamplifiers most of them 100v
electracoustic produced higly sophisticated 100 v systems with state of the art model XENIA that featured 5 Chanels / fire alarm conection / local monitor /zone paging / sellective auto power of units / cat 4 cable wiring ( at the time ) / priority microphone with selectable chimes ..... ( now all the above for the 1980 and completely designed and made in greece was a hell of a lot of technology )
the Electracousticalso constructed 2.5 KW multichanel dimmers ( 0-10V control) and a very special product called RUNNER that was actually a triple cassete deck that had inside car stereo BLAUPUNKT auto reverse engines and electronics enough inside to be able to play from song to song / from side to side / or from cassete to cassete between the three tapes .... that is F@cking inovative i think !!! for made in the 1980 it is what today will be a 5 disk CD player
this is what i remember from the 100v area and the times of 1980 in Athens ..please notice that in other smaller towns it could be more small factory copying each other from the above only DUblex is allive but construct only a few models any more the rest is chinese
in the PA area
bon studio constructed and put in the market clones of bryston working as quasi with 2N3773 fully protected and vi limmited
KRYPTON created by Tolis Mosxos bless his soul he is now RIP constructed amplifers based on the original applications of motorola and MJ15024-25 bery rowbust 3U sassi fully protected and ventilated models from 150-450 W happily working for years only had bad cooling and amplifier got dirty very easilly
TWIN Houlis-Trintafyllopoulos produced the brand name TWIN and was the first rela amlifiers with balanced inputs fully protected with input limmiters Vi limmiters thermostats ventilation channels dual mono and of course 2SA1302 - 2SC3281 outputs ...perfect machines made to last for ever
later on since the parteners no longer together AT brand was released that was an optimized version of TWIN all of them from 200-900 watt versions
JAZZ
was the amplifiers tha was made based on the J50 K135 applications and manufactured to work for the Alpha Sound PA company
ASD was the brand name of a smaller comapny tha produce bad clones of the all above but always had in mind to add a couple of transitors more to increase stability ...and that was working .... models from 70-400W but lower budget ...company is still active
STT electronics the complete cr@@p .... try to produce clones of the KRYPTON but while using mudular pcb but the construction was so terrible and the mistakes made inside was the one worst than the other had huge 4U sassi to produce bearly 150W that actually looked kinda masiive and impressive and that was good for the Greeks at the time but eventually all amps were trushed
of course there is more .... but lets say these are the names that have the History behind them
regards sakis
For the record i am placing a few words about the other amplifiers MIG at the time and some of them still going strong ....
in the 100V area
Dublex started with tube amplifiers mooved to transitors and as a sub constructor provided amplifiers for other brand names like the first Audio Brain ...and as seen the above GTH
ALVA did allmost copycuts of Dublex full range of 2N3055 amplifiers with mixers and mic preamplifiers most of them 100v
electracoustic produced higly sophisticated 100 v systems with state of the art model XENIA that featured 5 Chanels / fire alarm conection / local monitor /zone paging / sellective auto power of units / cat 4 cable wiring ( at the time ) / priority microphone with selectable chimes ..... ( now all the above for the 1980 and completely designed and made in greece was a hell of a lot of technology )
the Electracousticalso constructed 2.5 KW multichanel dimmers ( 0-10V control) and a very special product called RUNNER that was actually a triple cassete deck that had inside car stereo BLAUPUNKT auto reverse engines and electronics enough inside to be able to play from song to song / from side to side / or from cassete to cassete between the three tapes .... that is F@cking inovative i think !!! for made in the 1980 it is what today will be a 5 disk CD player
this is what i remember from the 100v area and the times of 1980 in Athens ..please notice that in other smaller towns it could be more small factory copying each other from the above only DUblex is allive but construct only a few models any more the rest is chinese
in the PA area
bon studio constructed and put in the market clones of bryston working as quasi with 2N3773 fully protected and vi limmited
KRYPTON created by Tolis Mosxos bless his soul he is now RIP constructed amplifers based on the original applications of motorola and MJ15024-25 bery rowbust 3U sassi fully protected and ventilated models from 150-450 W happily working for years only had bad cooling and amplifier got dirty very easilly
TWIN Houlis-Trintafyllopoulos produced the brand name TWIN and was the first rela amlifiers with balanced inputs fully protected with input limmiters Vi limmiters thermostats ventilation channels dual mono and of course 2SA1302 - 2SC3281 outputs ...perfect machines made to last for ever
later on since the parteners no longer together AT brand was released that was an optimized version of TWIN all of them from 200-900 watt versions
JAZZ
was the amplifiers tha was made based on the J50 K135 applications and manufactured to work for the Alpha Sound PA company
ASD was the brand name of a smaller comapny tha produce bad clones of the all above but always had in mind to add a couple of transitors more to increase stability ...and that was working .... models from 70-400W but lower budget ...company is still active
STT electronics the complete cr@@p .... try to produce clones of the KRYPTON but while using mudular pcb but the construction was so terrible and the mistakes made inside was the one worst than the other had huge 4U sassi to produce bearly 150W that actually looked kinda masiive and impressive and that was good for the Greeks at the time but eventually all amps were trushed
of course there is more .... but lets say these are the names that have the History behind them
regards sakis
Amp construction back then was very poor in general IME. Back then it was not uncommon for start ups to be home grown shed operations, especially in NZ at least.
Ive repaired several old Perreaux amplifiers from the 70s that looked like this. By the 80s, they were worlds apart. Early Mclaren(NZ brand) and Plinius were not alot better.
Whats 100V era?
Ive repaired several old Perreaux amplifiers from the 70s that looked like this. By the 80s, they were worlds apart. Early Mclaren(NZ brand) and Plinius were not alot better.
Whats 100V era?
true ... but since Background amplifier was also sold as kits i didnt want to imclude them ...
yeap !!! background was a copy of ETI 480 or so ... not realy a nice thing ... no protection at all no ventilators very low capacitance and marginal transformers ... sold as monoblocks 150W each (?? ) a nice box though ...black with an analog vu meter
yeap !!! background was a copy of ETI 480 or so ... not realy a nice thing ... no protection at all no ventilators very low capacitance and marginal transformers ... sold as monoblocks 150W each (?? ) a nice box though ...black with an analog vu meter
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