The 6DJ8 is prone to microphonics far in excess of any 12AT7. So you can make the 12AT7 sound more neutral.
90volts AC is kind of low but it will work.
The 6BX7 and 6BL7 both are good tubes, but when the output section saturates, there is not more than a watt or so of difference between them and the 6SN7.
90volts AC is kind of low but it will work.
The 6BX7 and 6BL7 both are good tubes, but when the output section saturates, there is not more than a watt or so of difference between them and the 6SN7.
Atma,
many thanks for reply.
As I said in previous post, I'm planning to build M60 with 12 6AS7G. I'm thinking to use 3 boxes for each channel, mechanically joined among them, so I don't use any interconnection cable and connectors.
As you can see in the attachment, the middle box contains amplifier section and lateral box PSU. All transformers (2 for output stage bridges, 6 for output stage tube filaments, 1 for input and driver stage, 1 for input and driver stage tue filaments) are placed into lateral boxes. So, I'm thinking to use layout as in the attachment to minimize current loss.
All filaments are heated in DC: transformers, bridges and the first CRC capacitors are placed in PSU units, then resistor and second capacitor in amplifier unit.
The same about output bridges supply: one capacitor only in PSU unit, resistor and the rest of capacitors in the ampli unit. A film cap will be placed close to each 6AS7G.
Also the same for input/driver stage: first capacitor in PSU unit, resistor, inductor and the rest of capacitors in amp unit.
Do you think is that the right way?
Andrea
Hi! This afternoon I run the Switching power supply for the filaments, One PS 7,5 Volts 40A has a pot for change the voltage between 5 and 8 volts. I put 20 6AS7 paralleled during one hour. The system become warm but stabilized in tour around 40ºC without rise.
I was afraid in cold system because the resistance near short circuit but run.
Now i will put the oscilloscope for watch for spurious signal. If this result I will avoid little transformer of 6,3 volt 50A.
I was afraid in cold system because the resistance near short circuit but run.
Now i will put the oscilloscope for watch for spurious signal. If this result I will avoid little transformer of 6,3 volt 50A.
I think this belong to ilusion
Formerly I asked twice for your above mentioned buyer's group and nobody said anything. While I Just getting the parts, I resolve partially the heaters. But maybe somebody want to integrate to this group and one of all the readers take control. For me one important thing are the Tubes, I need 20 x 6AS7G for each time I replace them plus 8 x 6H8C that is the practically more suitable because is reliable, cheap, undistorted, easy matchable, etc. Maybe somebody has a clue for them.
If you want to give continuity I will follow you.
Best Regards
Formerly I asked twice for your above mentioned buyer's group and nobody said anything. While I Just getting the parts, I resolve partially the heaters. But maybe somebody want to integrate to this group and one of all the readers take control. For me one important thing are the Tubes, I need 20 x 6AS7G for each time I replace them plus 8 x 6H8C that is the practically more suitable because is reliable, cheap, undistorted, easy matchable, etc. Maybe somebody has a clue for them.
If you want to give continuity I will follow you.
Best Regards
the ball is in Dr. Earfeelgood's (Ralph's) quarter!
Anyone else interested in a group buy for the cases at least? we need ten at least. If my memory serves me right the cases go for 450 USD each (you need two) but you get quality stuff with punched holes and look good for the family too.
Atma is selling the M-60 as a kit too costing 2100 US per monoblock if anyone is interested in a more all-rounded faster solution, and possibly financially less costly considering the time it takes in sourcing components.
So if anyone else is interested please raise your keyboard. Otherwise we forget about it and resort to metal fabrication.
dady- you can get conditioned tubes from Atma which go for 23 US, which is less than what other vendors charge.
Anyone else interested in a group buy for the cases at least? we need ten at least. If my memory serves me right the cases go for 450 USD each (you need two) but you get quality stuff with punched holes and look good for the family too.
Atma is selling the M-60 as a kit too costing 2100 US per monoblock if anyone is interested in a more all-rounded faster solution, and possibly financially less costly considering the time it takes in sourcing components.
So if anyone else is interested please raise your keyboard. Otherwise we forget about it and resort to metal fabrication.
dady- you can get conditioned tubes from Atma which go for 23 US, which is less than what other vendors charge.
If you will use 18 you need four more plus 6AS7
And better if you get 72 for next change of tubes. Are you sure If seriously you need such monster in summer time? Rise the SPL in the loudspeakers with a couple of dB you win with at least 8 or more tubes. With 18 tubes for channel you take 300watt of power, but you heat 567watt only in filaments + 300 watts in idle power = 860watt (without music) and Imagine that if you build an amplifier of 300watt per channel the most possible is you gonna use it for at least 100 watt per channel. Sum another 200 watts you rise the KW.
If you have this living room and you waste this amount of energy for listen music probably you have a lot of money, and in this case is easy for get directly to Atmasphere a MA3 amp or best.
Anyway i guess with a parallel 6SN7, or use one 6BX7 or 6BL7 you drive better the final bridge of 18 AS7.
Best regards
And better if you get 72 for next change of tubes. Are you sure If seriously you need such monster in summer time? Rise the SPL in the loudspeakers with a couple of dB you win with at least 8 or more tubes. With 18 tubes for channel you take 300watt of power, but you heat 567watt only in filaments + 300 watts in idle power = 860watt (without music) and Imagine that if you build an amplifier of 300watt per channel the most possible is you gonna use it for at least 100 watt per channel. Sum another 200 watts you rise the KW.
If you have this living room and you waste this amount of energy for listen music probably you have a lot of money, and in this case is easy for get directly to Atmasphere a MA3 amp or best.
Anyway i guess with a parallel 6SN7, or use one 6BX7 or 6BL7 you drive better the final bridge of 18 AS7.
Best regards
DIY as passion
Hi dady,
I don't like high efficiency loudspeaker system, obviously my point of view. Actually I own a pair of Linn S.A.R.A., 4 ohm 87 db SPL, but I'm planning to build an open baffle speaker system using low efficiency driver (86-87 db SPL), so the situation do not change.
About power consumption, I know that I need 1 KW, but also I know that I need the same power to cook a pizza, so I believe that I'll eat one less pizza when I'll lesten to music. BTW I listen to music not much than one hour in a day, and not all days of the week.
I do not have enough money to get MA2 or MA3 amp, and I like to build my devices.
I'm very curious to know what Atmasphere think about this project.
Also I would like to know what Atmasphere suggests about driver stage to properly drive 18 tube/channel.
Regards
Hi dady,
I don't like high efficiency loudspeaker system, obviously my point of view. Actually I own a pair of Linn S.A.R.A., 4 ohm 87 db SPL, but I'm planning to build an open baffle speaker system using low efficiency driver (86-87 db SPL), so the situation do not change.
About power consumption, I know that I need 1 KW, but also I know that I need the same power to cook a pizza, so I believe that I'll eat one less pizza when I'll lesten to music. BTW I listen to music not much than one hour in a day, and not all days of the week.
I do not have enough money to get MA2 or MA3 amp, and I like to build my devices.
I'm very curious to know what Atmasphere think about this project.
Also I would like to know what Atmasphere suggests about driver stage to properly drive 18 tube/channel.
Regards
Yes It would change
Hi Andrea!, Buona sera amico, I think the problem is you waste a lot of energy, I knew that pizza is an obligation further than art, is my point of view, better than caviar if i chose between them, and sometimes pizza is more important than music.
Dear friend, Atma said if you rise to 16 ohms the load you win at least the power by a four. The system become more alleviated and you can use real class A on step of multiply the number of tubes with the exclusively objective of going down the out impedance or use class near of B. Maybe you can use no efficient loudspeakers with 16 on step of 4, or put in series for rise the charge. He also said that has a guitar amp with few tubes in the output.
Tell me witch kind of loudspeakers you have or you project to make, maybe somebody can help to elucidate a better choice.
I know that arts are arts and many times not have a good explanation for them. But many times I awake some mornings and change my form of watch the life and its circumstances and this kind of hobbies make turnaround of impulse than efficient thinking. Every time i read a post of Diyaudio I change a little because i learn a little. I am a fun of this...
Avanti presto con brio!
Cari Saluti
Regards[/QUOTE]
Hi Andrea!, Buona sera amico, I think the problem is you waste a lot of energy, I knew that pizza is an obligation further than art, is my point of view, better than caviar if i chose between them, and sometimes pizza is more important than music.
Dear friend, Atma said if you rise to 16 ohms the load you win at least the power by a four. The system become more alleviated and you can use real class A on step of multiply the number of tubes with the exclusively objective of going down the out impedance or use class near of B. Maybe you can use no efficient loudspeakers with 16 on step of 4, or put in series for rise the charge. He also said that has a guitar amp with few tubes in the output.
Tell me witch kind of loudspeakers you have or you project to make, maybe somebody can help to elucidate a better choice.
I know that arts are arts and many times not have a good explanation for them. But many times I awake some mornings and change my form of watch the life and its circumstances and this kind of hobbies make turnaround of impulse than efficient thinking. Every time i read a post of Diyaudio I change a little because i learn a little. I am a fun of this...
Avanti presto con brio!
Cari Saluti
Regards[/QUOTE]
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You probably will want to keep the filter caps well away from the power tubes- heat is not good for filter caps!
With regards to the group buy- so far we've not seen enough interest. In the meantime we have begun offering the kit again. Its updated from the kit that discontinued 12 years ago
If we do see enough interest on the group buy we would still be fine with the deal.
Hi Ralph, how much is the kit right now?
Dear Atma, If is possible to say the actual price for the updated discontinued kit.
You probably will want to keep the filter caps well away from the power tubes- heat is not good for filter caps!
With regards to the group buy- so far we've not seen enough interest. In the meantime we have begun offering the kit again. Its updated from the kit that discontinued 12 years ago
If we do see enough interest on the group buy we would still be fine with the deal.
Dear Atma, If is possible to say the actual price for the updated discontinued kit.
[/QUOTE]
Dady
when I read a post I learn everytime more than a little, BTW like all people that read and post in this forum I have my own ideas, sometimes I change them, sometimes not.
At this time I own a pair of Linn Isobarik S.A.R.A. loudspeaker, drivers are 2 paralleled Kef B200 mounted in isobaric camera and 1 Scanspeak D2008, so 4 ohm and 87 db SPL, not an easy load for amp. I cannot modify them to mount woofers in series to take 16 ohm impedance, this is a commercial loudspeaker not a DIY project. So, I need current to drive it.
I'm planning to build in the future an open baffle loudspeaker with multiple driver, so surely I put them in series to get 16 ohm.
About high efficiency drivers, I don't like Fostex, Lowther, Supravox,.... In my point of view these drivers sound not realistic, high and low frequency are poor, mid are woody.
I'll very glad to find an efficient 5/7" mid-bass driver that sounds like KEF B110A (84 db SPL!), but I cannot find it at this moment.
Andrea
Well its not discontinuedDear Atma, If is possible to say the actual price for the updated discontinued kit.
The price is $4200.
Question
Only bridges bypass caps close to each power tube.
How many paralleled 6SN7 to drive 18 tubes/channel?
Thanks
Andrea
You probably will want to keep the filter caps well away from the power tubes- heat is not good for filter caps!
With regards to the group buy- so far we've not seen enough interest. In the meantime we have begun offering the kit again. Its updated from the kit that discontinued 12 years ago
If we do see enough interest on the group buy we would still be fine with the deal.
Only bridges bypass caps close to each power tube.
How many paralleled 6SN7 to drive 18 tubes/channel?
Thanks
Andrea
One seazon I used an amplifier instead of fireplace. It was hybrid amp prototype that consumed 1400 Watts total (my Tower project).
You can do it with 1 6SN7. You might get a few extra watts if you use two.