I'm starting with Gradiente STR-1250.
This is a small history of this.
This vintage Gradiente Model 1250 was made in the seventies... people turns
crazy with it’s panel ligths and colors, and the power was the average power
for those days..something alike 30 Watts RMS each channel over 4 ohms.
It was a result of agreement with JVC, as those days Gradiente was constructing
JVC models in my country.
The supply is not simetrical, voltage around 45 volts and condenser was used in
the output.
People fast increase the output electrolitic condenser to 6800uF and a 100n
capacitor was placed in parallell with it....also the input condenser was increased
Quiescent current, bias current, stand by current was increased to 50 miliamperes,
and some guys modified the transformer to 60 volts DC including another transistor
pair in the output.
Brazilian home parties where made with those units....normally connected to bass
reflex speakers, and also there was one unit with an active speaker and the other as
a passive sound damper.
I will post in this post, some Brasilian amplifiers...
Regards,
Felipe – Mod Evil
This is a small history of this.
This vintage Gradiente Model 1250 was made in the seventies... people turns
crazy with it’s panel ligths and colors, and the power was the average power
for those days..something alike 30 Watts RMS each channel over 4 ohms.
It was a result of agreement with JVC, as those days Gradiente was constructing
JVC models in my country.
The supply is not simetrical, voltage around 45 volts and condenser was used in
the output.
People fast increase the output electrolitic condenser to 6800uF and a 100n
capacitor was placed in parallell with it....also the input condenser was increased
Quiescent current, bias current, stand by current was increased to 50 miliamperes,
and some guys modified the transformer to 60 volts DC including another transistor
pair in the output.
Brazilian home parties where made with those units....normally connected to bass
reflex speakers, and also there was one unit with an active speaker and the other as
a passive sound damper.
I will post in this post, some Brasilian amplifiers...
Regards,
Felipe – Mod Evil
Attachments
Netlist said:It's nice to see gear from, at least for me, unknow brands.
This one looks highly modded.
Thanks for sharing.
/Hugo
Yeah...
In this Post, i send to you the Gradiente HA-II Schematic... The amp consists in two monoblocks... This is tested for the biggests Brazilian audiophiles...
A photo of Gradiente HA-II
The Techical Specifications:
Potência de saída por canal
170W RMS (8 Ohms, 0,04% THD, 20Hz - 20kHz)
250W RMS (4 Ohms, 0,06% THD, 20Hz - 20kHz)
180W (8 Ohms, Pot. máx. contínua*)
290W (4 Ohms, Pot. máx. contínua*)
210W (8 Ohms, Pot. máx. dinâmica**)
370W (4 Ohms, Pot. máx. dinâmica**)
500W (2 Ohms, Pot. máx. dinâmica**)
Potência de saída (BTL) mono
500W RMS (8 Ohms, 0,09% THD, 20Hz - 20kHz)
Impedância de saída
4 a 16 Ohms
Resposta de Freqüência
10Hz - 20kHz ( 1 Watt, 8 Ohms) +/-0,2dB
5Hz - 100kHz ( 1 Watt, 8 Ohms) -3dB
Distorção Harmônica Total (THD)
0,04% (8 ohms, 20Hz a 20kHz)
0,06% (4 ohms, 20Hz a 20kHz)
0,09% (BTL, 20Hz a 20kHz)
Distorção por Intermodulação
0,03% SMPTE, 8 Ohms (60Hz, 7kHz 4:1)
0,05% SMPTE, 4 Ohms (60Hz, 7kHz 4:1)
0,02% IHF, 8 Ohms (19kHz + 20kHz)
0,04% IHF, 4 Ohms (19kHz + 20kHz)
Fator de Amortecimento (Damping)
150 (1kHz, 8 Ohms)
Slew-rate
30V/us (20kHz, 8 Ohms)
Relação Sinal/Ruído
95dB (1W)
117dB (170W)
Separação entre canais
80dB (1kHz)
Sensibilidade
80mV para 1W (?)
1V para 170W
Impedância de entrada
25k ohms
Alimentação
110-120/220-240V (50/60Hz)
Dimensões
452 x 167 x 374 mm (LxAxP)
Peso
19,5 Kg
The Schamatic of the HA-II
Schematic
Thanks.
Nice thread Felipe, go ahead, there are many things to show
And not only Netlist will be happy to see foreign equipments, there are many others that will be happy to observe those things.
I suggest you to inform, not needed too much precision, more or less precised the manufacture year.
This HII....hummmm, 1987 to 1994 could be the period of manufacturing.
The A1 is older....gone near 1972 and up.
The Model 900 and Model 1250, those receivers, started 1970.
Those units where manufactured, in some period that importation was not allowed in our country...was an effort to create the capacity to produce everything, without the dependence of foreign countries...and we did that, but costed "zilion" dollares that we are still paying.
Very good thread Felipe.
regards,
Carlos
And not only Netlist will be happy to see foreign equipments, there are many others that will be happy to observe those things.
I suggest you to inform, not needed too much precision, more or less precised the manufacture year.
This HII....hummmm, 1987 to 1994 could be the period of manufacturing.
The A1 is older....gone near 1972 and up.
The Model 900 and Model 1250, those receivers, started 1970.
Those units where manufactured, in some period that importation was not allowed in our country...was an effort to create the capacity to produce everything, without the dependence of foreign countries...and we did that, but costed "zilion" dollares that we are still paying.
Very good thread Felipe.
regards,
Carlos
djk said:
Kinda makes one curious about the schematic of the HK630, DJK.
http://www.tnt-audio.com/ampli/hk630.html :
Parlando della sezione finale, anche qui vediamo rotture con la tradizione. All'ingresso, dei transistor duali (2SA1349, PNP) stanziano dove un tempo si trovavano transistor discreti NPN singoli. All'uscita, invece di uno stadio push-pull single ended con una configurazione a triplo Darlington, ora abbiamo due paia di transistor di potenza (2SD1148/2SB863, 140V, 10A, 100W, 15 MHz).
carlmart said:
Yeah! This is a Excelent project, and a Very old project! 18 years! ohhoo I can't imagine this HA-II with OPA627! In Brazil, a HA-II cost $350 to $400.
destroyer X, ohhh nice to see you in here.
jaccovermeulen and djk, Are you speaking about STR1250 or HA-II? If you're speaking of HA-II, this is a Brazilian Design.
Thanks to all replys.
I will post the schematic of Polyvox PM5000!
Polyvox PM5000
Polyvox PM5000.
Schematic:
Schamatic Link
Other lovely amplifier from Brazil, this is a Old amplifier, beautiful amplifier, with dual power supply.
Designed from Luíz Salvatore and Paulo Massa, based on a model from Dynaco.
You can see more images in here:
Image 1
Image 2
Image 3
Potência de saída por canal
150W RMS (8 Ohms, 0,5% THD, 1 kHz)
220W RMS (4 Ohms, 0,5% THD, 1 kHz)
200W IHF (8 Ohms, 0,5% THD, 1 kHz)
320W IHF (4 Ohms, 0,5% THD, 1 kHz)
Potência de saída mono (em ponte)
440W RMS (8 Ohms, 0,5% THD, 1 kHz)
600W IHF (8 Ohms, 0,5% THD, 1 kHz)
Impedância de saída
4 a 16 Ohms (Recomendado 8 ohms)
Resposta de Freqüência
10Hz - 80kHz (1W, 8 Ohms) -3dB
15Hz - 20kHz (Pot. Máx., 8 Ohms) -1dB
Distorção Harmônica Total (THD)
0,1% (1W, 8 Ohms, 20Hz - 20kHz)
0,15% (140W, 8 Ohms, 20Hz - 15kHz)
Distorção por Intermodulação
0,1% SMPTE, 8 Ohms (60Hz, 7kHz 4:1)
Fator de Amortecimento (Damping)
45 (1kHz, 8 Ohms)
Relação Sinal/Ruído
95dB (150W)
Sensibilidade
775mV para 150W, 8 ohms
Impedância de entrada
10k ohms
Alimentação
110-120/120-127/220-240/240-260V (50/60Hz)
Dimensões
480 x 160 x 411 mm (LxAxP)
Peso
21 Kg
Polyvox PM5000.
Schematic:
Schamatic Link
Other lovely amplifier from Brazil, this is a Old amplifier, beautiful amplifier, with dual power supply.
Designed from Luíz Salvatore and Paulo Massa, based on a model from Dynaco.
You can see more images in here:
Image 1
Image 2
Image 3
Potência de saída por canal
150W RMS (8 Ohms, 0,5% THD, 1 kHz)
220W RMS (4 Ohms, 0,5% THD, 1 kHz)
200W IHF (8 Ohms, 0,5% THD, 1 kHz)
320W IHF (4 Ohms, 0,5% THD, 1 kHz)
Potência de saída mono (em ponte)
440W RMS (8 Ohms, 0,5% THD, 1 kHz)
600W IHF (8 Ohms, 0,5% THD, 1 kHz)
Impedância de saída
4 a 16 Ohms (Recomendado 8 ohms)
Resposta de Freqüência
10Hz - 80kHz (1W, 8 Ohms) -3dB
15Hz - 20kHz (Pot. Máx., 8 Ohms) -1dB
Distorção Harmônica Total (THD)
0,1% (1W, 8 Ohms, 20Hz - 20kHz)
0,15% (140W, 8 Ohms, 20Hz - 15kHz)
Distorção por Intermodulação
0,1% SMPTE, 8 Ohms (60Hz, 7kHz 4:1)
Fator de Amortecimento (Damping)
45 (1kHz, 8 Ohms)
Relação Sinal/Ruído
95dB (150W)
Sensibilidade
775mV para 150W, 8 ohms
Impedância de entrada
10k ohms
Alimentação
110-120/120-127/220-240/240-260V (50/60Hz)
Dimensões
480 x 160 x 411 mm (LxAxP)
Peso
21 Kg
djk said:
Are you sure you have the model right?
The HK630 service manual I downloaded for that model (a receiver) has no resemblance to the Gradiente amp.
To start with the HA-II has symetrical LTPs at the input and a DC servo for the offset. The HK 630 has just one LTP and a blocking cap on the feedback.
In fact I have never seen an HK amp using a servo, but I don't know them all. What they usually do, and I think it's clever, use a trimming system injecting DC at the input to adjust the offset, like what they do on the HK770. That amp sounds very well (a friend of mine has it) and never seems to show any DC offsets.
Carlos
I supposed DJK was referring to the HA-II.
Shame about the 470 pF caps, probably needs it desperately with that much power coming from 6 *120 watts devices.
Swapping the LM741 DC servo opamp for an OPA627 i can not imagine either. An LF411 or an AD type would be a radical improvement, maybe an OPA132.
Cookies, anyone ?
Shame about the 470 pF caps, probably needs it desperately with that much power coming from 6 *120 watts devices.
Swapping the LM741 DC servo opamp for an OPA627 i can not imagine either. An LF411 or an AD type would be a radical improvement, maybe an OPA132.
Cookies, anyone ?
Attachments
The HK630 I was refering to was ca 1970, I didn't realize they were re-cycling old model numbers. The HK330/430/730 look similar to the Gradiente STR-1250, but have direct coupled outputs, the earlier HK630 was cap coupled like the Gradiente STR-1250.
Here is an old HK630
http://cgi.ebay.com/VINTAGE-HARMAN-...819507055QQcategoryZ67799QQrdZ1QQcmdZViewItem
Here is an old HK330 with only one row of push buttons like the Gradiente.
http://cgi.ebay.com/VINTAGE-HARMAN-...ryZ67799QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
The schematics for GAS/SAE look very similar to the Gradiente HA-II. The GAS Son had a tiered supply, the GAS Grandson a DC servo.
The newer HK Citation gear has the fully complementary push-pull design from input to output, and a DC servo, very similar to the Gradiente.
The Gradiente looks like interesting equipment.
Here is an old HK630
http://cgi.ebay.com/VINTAGE-HARMAN-...819507055QQcategoryZ67799QQrdZ1QQcmdZViewItem
Here is an old HK330 with only one row of push buttons like the Gradiente.
http://cgi.ebay.com/VINTAGE-HARMAN-...ryZ67799QQssPageNameZWDVWQQrdZ1QQcmdZViewItem
The schematics for GAS/SAE look very similar to the Gradiente HA-II. The GAS Son had a tiered supply, the GAS Grandson a DC servo.
The newer HK Citation gear has the fully complementary push-pull design from input to output, and a DC servo, very similar to the Gradiente.
The Gradiente looks like interesting equipment.
carlmart said:
http://www.hifichoice.co.uk/review_read.asp?ID=323
The "new" HK630 was sold here too.
The HA-II looks like fun to modify
(or rebuild, i have a shipload of each of the original HA-II device numbers. Oh no, not another Gradiente on my ""do before 80" list)
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