question about 6Av5ga tubes

[juanito]

Hi
I'm looking for an amplifier suitavble for my speakers fostex FE207E fullranges. There are my first DIY, and I would like to go for a tube amp. This is my first tube amp, so I would like your opinion in matching with one of these amps.

The first one would be The sophia elctric baby amplifier wich you probabilly all know, or at least is quite known in the net. I'll redirect just incase:
http://www.sophiaelectric.com/

I was olso considering the SE amp from nOrh, but the one wich olso has caught my attention is an AB, Push pull using the tubes 6AV5GA. This unit is build by ideal innovations, and there is very, very and very little info in the net. Only a few threads here at DIYaudio talk abot those tubes. the specs are by the seller:

Features:
Power Output Tubes - 6AV5GA’s well made in the USA by Sylvania in Pennsylvania in 1984. They are a very robust design with cathodes as large as a KT88’s. Originally made for demanding military video sweep applications, these tubes are ideal in an audio circuit and provide unrivalled sonic performance, at least in our opinion.
Driver Tubes - 12AX7WA/7025 made by Sovtek.
Controls - AC Power Switch, and two Level Controls. This amp can be driven directly from a CD player with excellent results.
Connectors – Power: IEC320 Inlet, Input: nickel plated RCA, Output: Binding Posts on ¾” centers. A 6 foot IEC power cord is included.
Circuit Protection – There are 6 internal fuses. Each output tube has its own cathode fuse, one fuse for the power transformer and a B+ fuse.
Documentation – This amplifier comes with a comprehensive owner’s manual.

Specifications:
Audio Power Output – Greater than 40 Watts DAP per channel or greater than 20 Watts RMS per channel – both channels driven simultaneously. For more info on Dynamic Audio Power visit: http://www.idealinnovations.biz/powerdefined.htm .
Frequency Response - 25 Hz to 22 KHz plus or minus 0.6dB.
Input Sensitivity - 1.2 volt RMS signal will provide full output.
Input Impedance – 100K Ohms.
Output Impedance – 8 Ohms.
Hum and Noise - Less than 1.5 millivolts or minus 56dB on the output jacks.
Power Requirements – AC 120 Volts 60Hz.
Power Consumption – Less than 85 watts idling and not more than 150 watts at full output.
Dimensions – 12.0”(305mm)Wide x 8.0”(203mm)Deep x 7.5”(190mm)High and weighs 22 LBS(10KG).

Components:
Transformers – All three, 1 power and 2 output are Canadian made to Ideal Innovation’s specifications and have been Hi-Pot tested at 1500 volts. The output transformers use M6 laminations and have screen taps at 43%.
Chassis – All custom made sheet metal finished in Santex powder coat for maximum durability and good appearance.
Other – Resistors are all flameproof and rated at 1 watt or more regardless of actual load and capacitors are all high quality for long life. Level control potentiometers are full size – not those little cheapies that wear out after a while. All tube sockets are ceramic with good quality pin sockets.
Serviceability – Should the situation ever arise, this amplifier can be repaired in minutes – not hours. Take a look in the photo provided and you’ll see a board that is easily accessed from both sides and no hot tube sockets mounted to it like many other brands

the name for it is elite-80. The price is more or less the one you could find for SE norh or sophia.

I would really apreciate much your help in chooseing, or making much clearer my desition in wich amp should I get. This is not definitive, they could be others.
Just whant to hear what you think about it.
As I sed before I'm complete newbie with tubes.
thanks very much for your attention and help in advance

Juanito

[Jim McShane]

The 6AV5 was used by Bogen in the DB-130 IIRC, and may have been used in other amps as well. From what I can recall of my Bogen experience, the key to the 6AV5 performance is the screen supply. The amp uses a regulated screen supply, and (obviously) runs the tubes in pentode mode. Again IIRC, the screen voltage ratings are much lower than the plate ratings.

Also, the 6AV5GA was the tube Sylvania/Philips internally triode-strapped and delivered to the US military as a 6B4G. People who've heard the tube say it sounds very nice!

I don't know the amps you are comparing, but even though it isn't as widely used as some, the 6AV5 seems to be capable of making very nice music.

[tubelab.com]

I found out about the 6AV5 tube a few years ago. I did some torture testing which was reported on in this thread:

Anyone know anything about a 6AV5GA?

and on my web site:

http://www.tubelab.com/6AV5.htm

I have found at least 7 different versions of the 6AV5 tube. They are all different with respect to their ability to handle abuse. The Sylvanias were the best in this regard. I have built SE and push pull amplifiers using these tubes and they do sound good, very good. An SE amp can deliver from 5 to 10 watts depending on how hard you want to push the tubes, and which version you are using. A push pull amp (screen drive, class B) can crank out an easy 80 watts using any version of the 6AV5.

These tubes never gained much popularity with the audio crowd, so they are still available cheap, if you are in the USA. They are not commonly available outside the US, and there is no substitute other than the 6FW5 which is very hard to find.

[juanito]

hi, thanks both of you.

Tubelab.com (should I call like that?) good morning over there (florida, and rest of east), I was just reading your site and experiment with 6AV5 while you posted the thread.
It looks very interesting alltoghether, though I have no idea about tubes. That's dificult to decide what amp to chose.
On one side ther is the famous sophia, wich is well known an reported, but I don't trust much good reviews; but then this one from ideal innovations looks interesting but totally oposite to the other one. I don't know....
What would you reccon

[tubelab.com]

I haven't paid too much attention to the tube amplifiers that are available commercially, and haven't heard either of the ones that you mention. Whatever amp that you choose, make sure that you can get tubes for it.

I was considering the 6AV5 tube for one of my amplifier designs (and I will still use it for a future design) when I was informed in several emails that 6AV5's are simply unavailable in Europe, Australia, and much of Asia. I don't know how true this really is though.

[jlsem]

This is from http://tubesandmore.com/. I stocked up on a few of these for a triode PP amp.



T-12AV5GA 12AV5GA - TETRODE, BEAM POWER $1.80

[frank754]

Wow, that's a nice price. Would love to see your results if you get a PP version going. Enjoyed tubelab's project & info as well.

[tubelab.com]

That sale price is no longer offered. I bought some of those as well as some 6AV5GT's which were even cheaper if I remember correctly. The 'GT is a diferent (6V6 sized) tube with a different sound. In fact it looks and sounds like a 6AU5. If you put these in a circuit running at 350 volts and 24 watts (I had a Sylvania 6AV5GA running fine at this level in SE) they will instantly self destruct. They are good for 10 to 12 watts max.

6AV5GA's can often be found in the US for $3 or $4.

[Jim McShane]

Originally posted by tubelab.com
there is no substitute other than the 6FW5 which is very hard to find.

If someone is in need of a few 6FW5s drop me a note. I probably have 6-8 of them I've accumulated over the years. The 6FW5 has higher ratings than the 6AV5GA too, IIRC.

Tubelab, thanks for the link to your 6AV5 tests, it was excellent reading. I learned a lot from it!

[juanito]

good morning
Yes i've got to check up if I can get these tubes in spain. But I don't see a problem in buying them throgh the net now a days.
Lukyly enogh, my brother lives in Salt lake City, so i could get them throgh him.
BTW, I decided to get the 6av5ga amp.
thnaks