Anyone know anything about a 6AV5GA?

[tubelab.com]

The 6AV5's cranked to about 37 watts of dissipation, about 3 times the recommended maximum. You will see the plate glowing, but I checked the screen grid carefully, and it was not glowing. This should aleviate any fears about violating the 175 volt screen rating. Most of the red glow comes from the pilot light on the power supply. The room lights were off for this picture. B+ is 380 volts, 355 volts across the tube, plate current is 105mA.

[tubelab.com]

And for tonights listening pleasure, the 6LW6, in triode mode. Setup is the same as before, except that it likes to be run hot (400 volts at 110 mA) with the 8 ohm load on the 16 ohm tap. This presents a 1500 ohm load to the tube. Power is 15 watts at .8% distortion. The single stage driver in this board does not have enough gain to drive this tube to clipping. Bass is the best that I have heard come out of my speakers. Note that all meters are slammed to the right, this amp wants more voltage, and more drive, I ran out of both.

[Tony]

hey tubelab,

did you run them 6LW6's thru G1 or G2? thanks.

[tubelab.com]

All of the testing that I did for this thread was in "triode strapped" mode, G2 connected to plate, drive on G1, since the original point was to see if a triode connected 6AV5 really could imitate a 6B4. After I did this, I listened to a few different sweep tubes for the next few nights and concluded that the 6AV5 really did sound good. It beats a triode strapped 6L6. The 6LW6 definitely had the best bass, but it wanted more drive, and more voltage than my power supply could give it. I was experimenting with that tube when an oops with the screwdriver blew up the CCS chip on the driver board. After fixing this, I set up to test triode strapped 807's and hurricane Wilma came along and spoiled the party. I will try screen drive once I put my lab back together.

[Fuling]

This is a very interesting thread!
I have a pair of Sovtek 6B4G (single plates) and I´m waiting for a pair of Billington Gold (chinese).
The plan is to build a DRD amp with Lundahl LL1664/60mA OPTS and LL1621/40mA wired as plate chokes for the driver stage.

Seems that I should ge me some of those 6AV5´s too then!

[slideman82]

Originally posted by quayhog
Look for a schematic of the Bogen DB-130. It uses 6AV5 tubes and it sounds surprisinly good. I use one for my worksop radio with a matching Bogen tuner. It has in interesting screen voltage regulator circuit using a 6CG7.

respect the screen limits though. I've also tried the 6AU5, it sounds OK and has a higher screen voltage limit.

It sounds interesting! Do this schematic is avaible on the net?

[tubelab.com]

I have the schematic in PDF format. It is almost 2 MB in size so I can't post it here. I don't see a way to include it in the forums email feature either. Send me an email via the forums email feature (or get the address off of my web site) and I will email it to you. Don't post your email address (or mine!) directly on this forum or any other place on the web in plain text format. Your mail box will be filled with spam in 2 days.

It is interesting that this amp operated the 6AV5's well above the published plate voltage ratings. Who would do such things?

[smoking-amp]

The Bogen DB-130 schematic is on the internet:
http://members.shaw.ca/pacifictv1/bogendb1301.jpg

[slideman82]

Well, thanks for the link! I'll take a look at it, and see what it looks like...

[jon_010101]

Interesting, I have a DB230 that also uses the 6AV5GA, and the schematic is quite different with a more reasonable ~400V on the output tubes. The driver stage is also a standard 7199 gain+cathodyne. I haven't rebuilt it yet, but it looks to have great potential, with regulated screens on the output tubes, and dual-mono supply except for the output B+.