6V6GT vs 6GB6G - Page 1
Forum section: electronics / beginners

author: Deactivated-1
author_rank: Frequent Contributor
timestamp: January 30, 2020, 01:11:04 am
content: is there any tone difference.I think most likely cause it's a really different construction by the lookwhy?cause 6GB6G's or the Russian 6P7S are really cheapwhile the Russian equivalent of the 6V6GT is also pretty cheap (6P6S) I still would want to use the 6P7S'sand you can probably see where I got the question I'm asking, the model numbers are really similar so I got the thought that it might be really similar.also while I'm on the topic of tubes the Russian 6N1P is the same as 12AU7 and 6N2P same as 12AX7?! is that right?I think but I tried using a 6N1P in a 6N2P circuit and got no output, might just be that I was using used tubes that were sitting in an attic since the 80s

author: Gyro
author_rank: Super Contributor
timestamp: January 30, 2020, 06:36:49 pm
content: No idea on the first part.Quote from: ELS122 on January 30, 2020, 01:11:04 amYes, they are electrically similar. Compare the datasheet pinouts though - 12A*** have centre tapped 6.3/12.6V heater. 6N** are 6.3V heater, no centre tap (they provide a screen between the two triodes instead). That would be a good reason for them not working.If buying 6n1P / 6n2p, then go for the -ev military spec versions from the Voskhod factory, they tend to have better element matching and lower distortion.P.S. If looking for low cost output tubes for triode configuration, also consider the GU50. Very tough and twice the Anode dissipation of the 6P7S. No high voltage anode top cap to worry about. Note that they are 12.6V heater though and very specific socket.

author: gbaddeley
author_rank: Regular Contributor
timestamp: January 31, 2020, 05:37:23 am
content: 6BG6B is similar to 6L6GT. This will have a different “tone” to 6V6GT, as the characteristics are different. AFAIK, 6V6 is an older lower powered tube.

author: gbaddeley
author_rank: Regular Contributor
timestamp: January 31, 2020, 07:51:35 am
content: Plate Dissipation is a physical limit. Power Output will be quoted with an operating class A, AB1, A2, push pull etc and usually a THD, eg 10%

author: Gyro
author_rank: Super Contributor
timestamp: January 31, 2020, 11:37:53 am
content: Quote from: ELS122 on January 31, 2020, 05:43:08 amYes, the GU50 is a Pentode, in fact is fairly unique in having G3 brought out to a pin rather than internally tied to the cathode (a few people have used this for optimising biassing, but you would normally connect to the cathode). It has a G2 limit of 250V (like the 6P7S) this is an issue for UL mode but it can happily be used at 400-450V (giving about 30W output) when triode wired, in fact I've seen triode connected curves up to 700V. You maybe want to consider why you want a mode switch - it causes extra complexity, and could cause havoc if you accidentally switch it with the power on.As gbaddeley says, just because a tube has a plate dissipation limit of 40W doesn't mean you have to use it at that, you can run at much lower dissipations with the benefit of greatly improved life.PS. they have a attractive 'modern' look if you snip off the (electrically isolated) metal cap and hot-swap knob from the top.

author: TimFox
author_rank: Super Contributor
timestamp: January 31, 2020, 02:30:23 pm
content: Do you mean 6GB6 or 6BG6? The latter is a repackaged 6L6 with a plate cap and different base pinout. It was very common when the US DoD dumped their spare tubes on the surplus market, since it was on the “preferred” list when tubes were active. I can’t find a listing for “6GB6”, only “6GB5”.

author: TimFox
author_rank: Super Contributor
timestamp: January 31, 2020, 08:49:19 pm
content: If you experiment with the 6BG6, be careful about the base diagram, which differs from 6V6, 6F6, 6L6, 6550, etc. in addition to the plate cap.

author: gbaddeley
author_rank: Regular Contributor
timestamp: February 01, 2020, 12:54:29 am
content: Just noticed 6BG6G looks like the venerable 807. However, the 807 has a 5 pin base. I have a few and they are readily available. Top Caps are a real down side for audio amps, as it means an ugly high voltage wire needs to be run above the chassis. That’s a reason why 6L6 6550 EL34 etc are more popular that their T.C. counterparts.

author: TimFox
author_rank: Super Contributor
timestamp: February 01, 2020, 02:23:48 am
content: Quote from: gbaddeley on February 01, 2020, 12:54:29 amApparently, after WW II, the military changed from 807 to 6BG6. Most beam power tubes with 6.3 V, 0.9 A heaters are 6L6 with slight variation.