heres my next idea.
OPTs et al are on the way, but i went to test my 807s, and one is shorted
main amp (each channel)
I wrote 12AX7 but meant 12AU7, oops..
power supply.
eye tube VU deal.
(need to change this some.. that voltage divider won't work.. too high impedance. I suppose ill just jack up the plate resistors some, on the eye..)
thoughts, etc?
OPTs et al are on the way, but i went to test my 807s, and one is shorted
main amp (each channel)
I wrote 12AX7 but meant 12AU7, oops..
An externally hosted image should be here but it was not working when we last tested it.
power supply.
An externally hosted image should be here but it was not working when we last tested it.
eye tube VU deal.
(need to change this some.. that voltage divider won't work.. too high impedance. I suppose ill just jack up the plate resistors some, on the eye..)
An externally hosted image should be here but it was not working when we last tested it.
thoughts, etc?
SOME THOUGHTS.
Hi,
First of all I'd recommend a 6SN7 iso the 12AU7.
Never liked the sound of the 12AU7.
Or consider a 12BH7A or 12FQ7/12CGFA.
You can also safely ommit the input cap.
Also I would up the filter cap after the choke by putting a # of caps in //.
Up to 500 microF wont do any harm.
Seems you forgot the heaters too.
Cheers,
Hi,
First of all I'd recommend a 6SN7 iso the 12AU7.
Never liked the sound of the 12AU7.
Or consider a 12BH7A or 12FQ7/12CGFA.
You can also safely ommit the input cap.
Also I would up the filter cap after the choke by putting a # of caps in //.
Up to 500 microF wont do any harm.
Seems you forgot the heaters too.
Cheers,
UP TO THE USER?
Hi,
Not so.That's up to the user...he may use something called a preamp,n'est-ce pas?
Much more interesting would be to couple V1 to the 807 directly.
Ciao,
Hi,
You also forgot a volume control.
Not so.That's up to the user...he may use something called a preamp,n'est-ce pas?
Much more interesting would be to couple V1 to the 807 directly.
Ciao,
Yeah, I might try something else for gain.
just kickin' the idea around for now. I have a few 6CG7's, might try them. no 6SN7s though, but they're the same tube, up to a point..
I'll probably throw on volume control when I actually make it, but im usually too lazy to draw it in
just kickin' the idea around for now. I have a few 6CG7's, might try them. no 6SN7s though, but they're the same tube, up to a point..
I'll probably throw on volume control when I actually make it, but im usually too lazy to draw it in
Colt45 said:but i went to test my 807s, and one is shorted
I have quite a few of these...i could spare 1 or more ...
What iron did you order?
dave
Re: Re: next project
That would be great
For iron i ordered some 5k : 8 old stock stuff from triode electronics. I'll have to see how they sound, I guess
planet10 said:I have quite a few of these...i could spare 1 or more ...
What iron did you order?
dave
That would be great
For iron i ordered some 5k : 8 old stock stuff from triode electronics. I'll have to see how they sound, I guess
Re: SOME THOUGHTS.
I like 807s, a very nce underrated tube. Someone said recently (perhaps Grand Poohbah dave) that he thought their general lack of popularity was due to topcaps. I'd agree, but that's good, because I like topcaps.
Filter capacitance is always nice, providing it's as good as some of the modest caps, so I prefer to // lots of smaller ones.
AC heaters will be fine, and less hassle. Bias the heaters about 40V above ground.
Yep. The more amps I build, the more I find the driver is a lerger determinant of the sound. You could also try ECC99, 6H30 or 6N1Ps (if you want to try some of the 6N1Ps, send me your address and I'll send you a couple)fdegrove said:Hi,
First of all I'd recommend a 6SN7 iso the 12AU7.
Never liked the sound of the 12AU7.
Or consider a 12BH7A or 12FQ7/12CGFA.
I like 807s, a very nce underrated tube. Someone said recently (perhaps Grand Poohbah dave) that he thought their general lack of popularity was due to topcaps. I'd agree, but that's good, because I like topcaps.
Ditch the input cap.You can also safely ommit the input cap.
Also I would up the filter cap after the choke by putting a # of caps in //.
Up to 500 microF wont do any harm.Seems you forgot the heaters too.
Filter capacitance is always nice, providing it's as good as some of the modest caps, so I prefer to // lots of smaller ones.
AC heaters will be fine, and less hassle. Bias the heaters about 40V above ground.
No, it's the thing that made the music redundant.Joel said:That's the definition of the "digital revolution"... the thing that made the preamp redundant.
Vinyl rules!
Did you want the 807s to be triode wired? If so, connect the screen and the plate together at the tube socket.
BTW, the best 807 datasheet is at http://www.retrovox.com.au/STC807.pdf
Beware, it's 5.5M
Cheerio.
BTW, the best 807 datasheet is at http://www.retrovox.com.au/STC807.pdf
Beware, it's 5.5M
Cheerio.
807
Hi,
The thread where we briefly touched upon the 807:
RALPH POWER AMP
This one is about a PP 807 amp:
807 PP
Just for info:
The 807 was often used in military radio tramsmitters,there must still be zillions around.
It is a close relative of the 6L6/KT66 tubes and is pretty linear in pseudo-triode mode.
Cheers,
Hi,
The thread where we briefly touched upon the 807:
RALPH POWER AMP
This one is about a PP 807 amp:
807 PP
Just for info:
The 807 was often used in military radio tramsmitters,there must still be zillions around.
It is a close relative of the 6L6/KT66 tubes and is pretty linear in pseudo-triode mode.
Cheers,
Thanks guys.
I think i'll try it full blow pentode mode at first, maybe make it switchable to triode..
807 has another brother (other than 6L6 et al). 6BG6G is a octal based 807 with none of that shielding stuff under the mica on the bottom.. slightly less glorious job as a TV sweep.
I think theres something kind of neat about the 'ol 5pin socket though
I think i'll try it full blow pentode mode at first, maybe make it switchable to triode..
807 has another brother (other than 6L6 et al). 6BG6G is a octal based 807 with none of that shielding stuff under the mica on the bottom.. slightly less glorious job as a TV sweep.
I think theres something kind of neat about the 'ol 5pin socket though
807 is what you use if you're not man enough for a 1625.
They saw service in civilian apps, too- I remember using them in a HF transmitter I built maybe 35 years ago. Ran them waaaaay over their ratings for CW service. If you kept the key down too long, the plates would go off like a flashbulb. The transmitter would only work if you kept your speed above 20 wpm.
But, yeah, they're basically just 6L6s.
They saw service in civilian apps, too- I remember using them in a HF transmitter I built maybe 35 years ago. Ran them waaaaay over their ratings for CW service. If you kept the key down too long, the plates would go off like a flashbulb. The transmitter would only work if you kept your speed above 20 wpm.
But, yeah, they're basically just 6L6s.
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