So What Is Closest to a 6AQ5, but Lower Power?

[Andy Le Blanc]

I appreciate that response......its a very subjective thing to compare differing tube types.....

[lastwinj]

7701

[RJ Guitars]

S2 - I've been chasin' big tone in small tubes for a long time and I've found several answers. I'm inclined to believe that the human ear really hears things better when it's louder and thus leads us to believe amps sound better when they get louder... another topic all on it's own.

I've used a bunch of different 7 pin tubes icluding: 6AK6, 9001, 6AK5, 6AQ5, 6AN5, 6AG6, 6AU6... but I think the best sound I ever got was from an EL95. Very EL84ish in sound, but only 3 or 4 watts. A 6AK6 is my next favorite with more of a 6V6 sound to me.

I've also tried several triode outputs in push pull and had reasonable success. My all time favorite small venue gig amp is an ecc99 PP triode. See this older post if your interested...

https://tubeamparchive.com/viewtopic.ph ... highlight=

The 6AK5, 6AN5, and the 9001 are really short stubby rascals and if you want to make something really small, these are kinda interesting... but didn't sound as good as the others I mentioned.

Please post back with us when you get something going, I'd be quite curious what you come up with.

rj

[harryk]

RJ! When you made an amp with EL95 tubes, was it a single ended or push pull configuration? How much voltage you had in power tube plates and what was dissipation? What kind of PI did you have in it? My aim is to make an amp with Express preamp with 2xEL95 tubes. I am glad to hear that those bottles are nice ones because I happen to have a pair of them in my stash and would like to use them to some project. Regards Harry

[RJ Guitars]

RJ! When you made an amp with EL95 tubes, was it a single ended or push pull configuration? How much voltage you had in power tube plates and what was dissipation? What kind of PI did you have in it? My aim is to make an amp with Express preamp with 2xEL95 tubes. I am glad to hear that those bottles are nice ones because I happen to have a pair of them in my stash and would like to use them to some project. Regards Harry

Harry,

It has been awhile since I did this, but I found the drawing that I started with... the voltages listed I think I put down as place holders and they are not real. If I recall correctly, my power transformer was 250-0-250. I'll see if I can bring myself to open that amp up and take some honest measurements and then update the drawing. Don't hold up your project waiting though cuz I'm slower than molasses on these kinda things...

Anyway, my amp was a single ended amp that I was using to compare various output tubes. As you can see, I could exchange 8 pin, 9 pin, and 7 pin tubes. In the end I got the very best sounds out of this amp using either a el84 or an EL95. I had originally designed it around the 6G6 octal, but that didn't sound too good. In the photo I attached it has the EL84 in it.

In all honesty, I did not invest enough in tweaking this to any specific tube, but rather swapped tubes around I got a good sound. Better technique would really be in order to make the most out this design... I'm lazy enough that once it started sounding cool, I started using it and never made it back to really study it.

The one thing that I did think was significant was that the sound of the EL95 was so similar to the EL84... just less of it.

rj

[harryk]

Thanks RJ! I am still finishing my present project, a modified Deluxe 5E3 which should be ready by some weeks. After it is ready, I`ll start my push pull EL95 or EL90 (6AQ5) project. I could put both tubes in it, because the other one is a small EL84 and the other one is a small 6V6 if I remember right. I could do own master volumes for both pairs of tubes. I will be back when that project proceeds. If you want to check my buildings, please go to my web pages www.bluetone.fi Regards Harry

[Doug H]

6EM7's are fun to play with. They are octal dual triodes which were used for video circuits. With two, you can use the high Rp section for the LTP and use the low Rp section for a push-pull output stage. I think I was getting around 3-5W when I was experimenting with them with a 208VAC iso xformer. Like someone else mentioned about another tube- they don't color the tone much, except to warm it up a little. It takes a pretty hot signal to drive them. But if you have a good sounding preamp they can be fun to play with.

I'm thinking of building a "baby wreck" with a pair of EL91's. They are 7-pin pentodes that will produce about 5W push-pull class AB at around 250V. I've read good reports about them.

[lastwinj]

if yer looking for a REALLY small tube to use for output, try a 6HA5. 7pin maybe an inch high.

germ

[harryk]

I ended up to following topology with my next tube amp project. One preamp channel will be Express and the other channel some cleaner one with one 12AX7. Poweramp will be with one pair of 6AQ5 and one pair of 6DL5 in parallel to same OT which is Hammond 1615 with 5 kohm primary. With this combination I try to capture EL84 and 6V6 tubes sound palette with a reasonable noise level. Harry