Hello. I'm new here. In recent days, I get facinated with the minature tube 6AQ5 and is eager to build a amp. with it as the power tube. To better understand this tube, I decide to find its curve chart for further study. However, what is disppointing is that it takes me a long time to look for such chart with no result, though it is said that this tube was once very popular, particularly in WWWII and is still in large stock today. I'll be really appreciated if anybody would share concerned information with me.
PS.: The most interesting chart for me is the one describing the relationships between its output power, the distortion rate and the plate load resistance. I want to figure out the optimal plate load resistance.
Looking foward to your warm help. Thanks in anticipation.
PS.: The most interesting chart for me is the one describing the relationships between its output power, the distortion rate and the plate load resistance. I want to figure out the optimal plate load resistance.
Looking foward to your warm help. Thanks in anticipation.
Hi,
Actually it's a small beam tetrode. 6AQ5/EL90 good 4.5W dissipation as a SET.
You can have a look here:
DUNCAN AMPS
Cheers,
Actually it's a small beam tetrode. 6AQ5/EL90 good 4.5W dissipation as a SET.
You can have a look here:
DUNCAN AMPS
Cheers,
Following the links there, we find a 6 page GE data sheet : http://www.mif.pg.gda.pl/homepages/frank/sheets/093/6/6AQ5.pdf
and a 10 page Lorenz data sheet: http://www.mif.pg.gda.pl/homepages/frank/sheets/093/6/6AQ5.pdf
both have the distortion vs. power output curve.
and a 10 page Lorenz data sheet: http://www.mif.pg.gda.pl/homepages/frank/sheets/093/6/6AQ5.pdf
both have the distortion vs. power output curve.
OK, I screwed up the link to the Lorenz data sheet (both are on Frank's site mentioned above). It's http://www.mif.pg.gda.pl/homepages/frank/sheets/062/e/EL90.pdf
The Lorenz data sheet is the one I used to design the 6AQ5 amp here: http://www.audiophool.cjb.net/Audio.html
The Lorenz data sheet is the one I used to design the 6AQ5 amp here: http://www.audiophool.cjb.net/Audio.html
Is Voice of Music 1448 a PP machine? or a SE with each two 6AQ5s for each channel?
Nice to meet you, Zombie.
Is that machine, Voice of Music 1448, a P-P one? I know little about vintage gears, and I find on the web that 6EU7 is a twin triode, so I guess the usage of the three 6EU7s is: one for preamp, two for phase spliting of each channel and naturally the four 6AQ5s are working in P-P mode. How much is its output power, 10 Watts? Have you ever compared 6AQ5 working in SE mode and P-P mode? Sorry for so many questions. I am very interested in what kind of magic this small beam tube is going to show me.
Nice to meet you, Zombie.
Is that machine, Voice of Music 1448, a P-P one? I know little about vintage gears, and I find on the web that 6EU7 is a twin triode, so I guess the usage of the three 6EU7s is: one for preamp, two for phase spliting of each channel and naturally the four 6AQ5s are working in P-P mode. How much is its output power, 10 Watts? Have you ever compared 6AQ5 working in SE mode and P-P mode? Sorry for so many questions. I am very interested in what kind of magic this small beam tube is going to show me.
Hi Kenneth!
It's a P-P and it's 25W per channel on the spec sheet.
I haven't compared P-P vs SE. I will change all the caps and some other components first, later maybe I will experiment with it.
There might be smth about the 6AQ5 on Audioasylum
Do the search in the relevant forums, like Tubes, DIY and Vintage.
Cheers,
Tom
It's a P-P and it's 25W per channel on the spec sheet.
I haven't compared P-P vs SE. I will change all the caps and some other components first, later maybe I will experiment with it.
There might be smth about the 6AQ5 on Audioasylum
Do the search in the relevant forums, like Tubes, DIY and Vintage.
Cheers,
Tom
something off-topic
Audio Asylum is a good place to visit. But the speed of server is slower than here and it is difficult to post image there, perhaps due to the limited capacity of the rented storage. I always lose patience and can't help jumping to other sites when refreshing the webpage of Audio Asylum. That's why I was extremely excited when I found this place.
Audio Asylum is a good place to visit. But the speed of server is slower than here and it is difficult to post image there, perhaps due to the limited capacity of the rented storage. I always lose patience and can't help jumping to other sites when refreshing the webpage of Audio Asylum. That's why I was extremely excited when I found this place.
Something weird
I studied the GE characteristic curve chart but found something comfusing. Coventionally, the plate load resistace for 6V6 or 6AQ5 will fall within the 5K to 7K range, which is manifested in many classical designs. However, according to the chart as following, I have to draw a conlusion that the optimal plate load resistance shall be around the 6K point rather than the widely used 5K benchmark. I've got completely confused 'cause my schematic, a classical design, chooses 5k as the primary resistance of OPT, and according to above conclusion, such choice may not be optimal. Can anybody help me to show an explanation?
I studied the GE characteristic curve chart but found something comfusing. Coventionally, the plate load resistace for 6V6 or 6AQ5 will fall within the 5K to 7K range, which is manifested in many classical designs. However, according to the chart as following, I have to draw a conlusion that the optimal plate load resistance shall be around the 6K point rather than the widely used 5K benchmark. I've got completely confused 'cause my schematic, a classical design, chooses 5k as the primary resistance of OPT, and according to above conclusion, such choice may not be optimal. Can anybody help me to show an explanation?
Attachments
Still bewildered
And what truly confuses me and is still lingering for reasonable explaination is the choice of optimum load resistance of 6AQ5. I've browsed all the schematics available at my hands and regretfully found that if 6AQ5 is working as a beam tetrode, the OPT will choose 5K as its primary resistance without exception. I really wonder why the designers have not chosen 6K, as the above chart shows. Yes, it is true that the characteristic curve of tubes manufactured by various manufactures may differ from each other, but how come that the designers unanimously choose 5K as the best choice? Still waiting for an answer.
And what truly confuses me and is still lingering for reasonable explaination is the choice of optimum load resistance of 6AQ5. I've browsed all the schematics available at my hands and regretfully found that if 6AQ5 is working as a beam tetrode, the OPT will choose 5K as its primary resistance without exception. I really wonder why the designers have not chosen 6K, as the above chart shows. Yes, it is true that the characteristic curve of tubes manufactured by various manufactures may differ from each other, but how come that the designers unanimously choose 5K as the best choice? Still waiting for an answer.
Odd harmonic distortion?
Just a wild guess here but perhaps the tube sounds best at something other than "lowest total distortion" point given on the curve? That is, perhaps the odd harmonics are too high at 6k and is better at 5k? Maybe the 3rd and 5th are lower at 5k with 2nd higher proportionately?
Rick
Just a wild guess here but perhaps the tube sounds best at something other than "lowest total distortion" point given on the curve? That is, perhaps the odd harmonics are too high at 6k and is better at 5k? Maybe the 3rd and 5th are lower at 5k with 2nd higher proportionately?
Rick
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