next project - Page 2

Colt45 · 30th December 2002, 05:31 AM

Quote:

Originally posted by planet10

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

Brett · 30th December 2002, 08:43 AM

Quote:

Originally posted by fdegrove
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.

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)

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.

Quote:

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.

Ditch the input cap.
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.

Brett · 30th December 2002, 08:44 AM

Quote:

Originally posted by Joel
That's the definition of the "digital revolution"... the thing that made the preamp redundant.

No, it's the thing that made the music redundant.

Vinyl rules!

Brett · 30th December 2002, 08:48 AM

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.

fdegrove · 30th December 2002, 11:51 AM

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,

Colt45 · 30th December 2002, 06:47 PM

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

fdegrove · 30th December 2002, 06:50 PM

Hi,

Yep.

Westrex used these on some theatre amps.

Cheers,

SY · 30th December 2002, 07:04 PM

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.

30th December 2002, 11:51 AM	#15
fdegrove diyAudio Senior Member Join Date: Aug 2002 Location: Belgium	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, __________________ Frank

30th December 2002, 06:50 PM	#17
fdegrove diyAudio Senior Member Join Date: Aug 2002 Location: Belgium	6BG6 Hi, Yep. Westrex used these on some theatre amps. Cheers, __________________ Frank

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
CDPRO2 Group Project (open source project)	BrianGT	Digital Source	147	8th August 2008 11:37 AM
My OLD Project....... cheap tube audio project!!!	tube-lover	Tubes / Valves	4	8th May 2008 09:26 PM
first project	ceebmoj	Full Range	5	23rd January 2008 07:51 AM
My first project, cool project.	sorinsistem	Solid State	3	19th January 2006 05:08 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

30th December 2002, 08:48 AM	#14
Brett diyAudio Member Join Date: Jan 2002	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.

30th December 2002, 06:47 PM	#16
Colt45 diyAudio Member Join Date: Feb 2002 Location: Canada	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

30th December 2002, 07:04 PM	#18
SY diyAudio Moderator Join Date: Oct 2002 Location: Chicagoland Blog Entries: 1	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.