Finished
Well, with a lot of planning, and some improvisation, I managed to plant 9 Philips bypass CAPs on the power supply...
6 hours cutting and bending solid core wire for the connections, they are so big, they dont fit where needed, glue them using TESA tape, solder evrything in place, burned fingers, etc...
Meanwhile, the first snow falling all morning, when I went to take the picture, it was so dark, this was the best I could do with my mobile phone...
As for the sound, I expected to remove the faint SCHHH I can hear with my ear very close to the speaker, but it is the same...
On the other hand, bass feels stronger, and there is significant better separation, worth the trouble...
There is not much more worth doing to this amplifier, different yes, so far I am quite happy with my choices...
Well, with a lot of planning, and some improvisation, I managed to plant 9 Philips bypass CAPs on the power supply...
6 hours cutting and bending solid core wire for the connections, they are so big, they dont fit where needed, glue them using TESA tape, solder evrything in place, burned fingers, etc...
Meanwhile, the first snow falling all morning, when I went to take the picture, it was so dark, this was the best I could do with my mobile phone...
As for the sound, I expected to remove the faint SCHHH I can hear with my ear very close to the speaker, but it is the same...
On the other hand, bass feels stronger, and there is significant better separation, worth the trouble...
There is not much more worth doing to this amplifier, different yes, so far I am quite happy with my choices...
An externally hosted image should be here but it was not working when we last tested it.
I put back the JJ KT77, they are beautiful and sound smooth, now all my tubes are militar specs, supposed to last over 10.000 hours. I will sit back and listen... 
Not to loose practice, I am designing my own amplifier...
LOWRIDER, of course, 3x 300B per channel, input and interstage will be under the hood, based on Sakuma design and Linn Olson theories, only on paper so far, but who knows one day...
Not to loose practice, I am designing my own amplifier...
LOWRIDER, of course, 3x 300B per channel, input and interstage will be under the hood, based on Sakuma design and Linn Olson theories, only on paper so far, but who knows one day...
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
Tube_Dude said:Hi Lowrider
It seams that exist an error in your schematic.
R18 and R19 must be connected between the pin 8 of the EL34 ( cathode ) and ground.
It is used to measure bias.
Maybe the error is only in the schematic and not in the implementation...
Welcome!!
You are right, when I did the check you sugested, I forgot that looking from the top, the terminals are anti-clockwise...
This is how the schema should be:
An externally hosted image should be here but it was not working when we last tested it.
Hi Katapum,
Long time no see, where have you been hanging ?
Since the JJ KT77 settled, I dont need another amplifier, with my speakers it sounds just as I like, full body, quick punchy bass, life like mids and highs that make me chiver...
I did order a quad of Shuguang KT66, some say they sound even better than KT77, not too expensive to try...
Long time no see, where have you been hanging ?
Since the JJ KT77 settled, I dont need another amplifier, with my speakers it sounds just as I like, full body, quick punchy bass, life like mids and highs that make me chiver...
I did order a quad of Shuguang KT66, some say they sound even better than KT77, not too expensive to try...
El Cheapo uses 12AT7, 60u amplification, my E80CC have 27u and the 6SN7 20u...
With two stages mine still has less gain, also my input stage beeing symetric, as the Aikido, only has half of the amplification of the used tube, and I removed the input stage cathode capacitor, meaning it has low enough gain...
With two stages mine still has less gain, also my input stage beeing symetric, as the Aikido, only has half of the amplification of the used tube, and I removed the input stage cathode capacitor, meaning it has low enough gain...
Didnt like the look of the plastic Philips MKP anymore, so I got rid of all 15 I had installed over time...
8 simply removed, 7 replaced by several NOS capacitors: 2 FT-3 + 1 K75-24 + 4 Siemens PIO dated 1965, no room for more...
My amplifier...
8 simply removed, 7 replaced by several NOS capacitors: 2 FT-3 + 1 K75-24 + 4 Siemens PIO dated 1965, no room for more...
My amplifier...
Murphys law...
Installed Shuguang KT66, BIAS set to minimum, one measured 52mA, the others less, moved them to different positions, all still measured the same, adjusted bias to 52mA for all... After almost a week, nothing changed...
All this time I have been worrying with BIAS constantly changing, afraid the amplifier was not stable, changing supply capacitors, diodes, adding bypasses, etc... After all it was just the JJ KT77...
All is well that ends well, the new tubes sound very good, slightly less body than the 77, but livelier, they stay...
Installed Shuguang KT66, BIAS set to minimum, one measured 52mA, the others less, moved them to different positions, all still measured the same, adjusted bias to 52mA for all... After almost a week, nothing changed...
All this time I have been worrying with BIAS constantly changing, afraid the amplifier was not stable, changing supply capacitors, diodes, adding bypasses, etc... After all it was just the JJ KT77...
All is well that ends well, the new tubes sound very good, slightly less body than the 77, but livelier, they stay...
Today I will listen to my system for the last time in months, maybe years...
Tomorrow the movers take it to Portugal, where it will be stored until I have a new home somewhere...
I am leaving Latvia saturday, then, early September, I will go to Africa, Angola...
My first job was there in 1974, I have been dreaming that my last will be there too, this is my chance... :roll:
Tomorrow the movers take it to Portugal, where it will be stored until I have a new home somewhere...
I am leaving Latvia saturday, then, early September, I will go to Africa, Angola...
My first job was there in 1974, I have been dreaming that my last will be there too, this is my chance... :roll:
An externally hosted image should be here but it was not working when we last tested it.
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