tube selection

[stingray_65]

OK.
I just finished the amp and cab (minus tolex and hardware) and I am about to purchase tubes.

I built a 5e3 clone using part values as discribed by the original schematic.
the mods I've made include a safer modern grounded main and a standby switch.

as i keep reading this forum and other tweed amp builders sites I'm realizing that this little amp is extremely acceting of a variety of tubes

for the preamps i'm getting the impression that any 12xx7 will work in V1&2 so long as V1 gain is less or equal to V2

for a power i can use 2 6V6 or 6L6's

What are some of my other options?

pre amp:
7025?
others?

power tubes
KT66?
others?

recto
5U4G? 5AR4?
others?

I'm looking for plug n play and not having to upgrade components

I'm looking to just get it up and going beg borrowing from friends amps while I save up for a great set of vintage RCA's

thanks

[black_labb]

a poir of 6l6's usually warrants a new ot, but using the one in there would work, but you probably wouldnt get too much power from it (either from impedance matching or the limited ot). should be able to use other rectifiers if you have enough current available on the 5v winding. that would increase the voltage as well.

[tubeswell]

Also you need to watch your PT heater winding ratings. 6L6s use 900mA heaters whereas 6V6s use 450mA, so if you 'upgrade' to 6L6s, there's about an extra Amp required on the 6.3V winding for a start. (But maybe your PT already has a 3A heater winding?) Also you might want about 150mA-180mA on the HT winding for 2 x 6L6s. (KT88s - even more)

Either 5AR4 and 5Y3Gt can work off a 2A 5V winding. 5U4G requires 3A

You might need to check that the bias once you put the higher voltage tubes and rectifier in. I built a 5E3 for 6V6s or 6L6s it works okay with either type without changing the 250R shared cathode resistor, as long as I put in a 5AR4 for the 6L6s and a 5Y3GT for the 6V6s. But I also have multiple taps off the OT secondary so I can swap the 8R speaker to the 16R tap to get the Primary zeds down to around 4k for the 6L6s (or 8k for the 6V6s). On the other hand a 6k6 load can work equally well for a pair of 6V6s or 6L6s in push pull - depends what you have in the way of zeds.

[stingray_65]

pt specs

600vct @100mA dc

6.3VCT @1.65A

5V @2A

ot specs
6600 ohms CT

4/8 ohms out wired for 8 ohms to a weber 12" alnico 25 watt speaker

[MWJB]

Stick to 6K6/6V6 power tubes. 6L6/5881/EL34/KT66 will fry your PT. Your PT is rated a little lower than typical 5E3 with respect to heater current and B+ voltage. Your amp will probably take GZ34/5AR4, or SS rectifier without any changes, if running 6V6s.

Your OT primary Z is a shade lower than the 5E3s 8.5K.

7025 was a lo noise, military spec 12AX7...no longer really exists unless you are buying NOS. Any decent 12AX7 should have good gain & lo noise.

12AU7/12AY7/12AT7/5751/12AX7/ECC83 will all function in any preamp socket. You could even use 12DW7 in either socket, this will give a lo gain normal/mic channel and a regular gain bright/inst channel in V1, or drop gain right before the PI if used in V2 (harp players sometimes do this)...however which sounds best is another story.

[wyatt]

That 2A's on the 5V means no 5U4. You can run 5Y3, 5V4, 5AR4, 5R4, all of those are 2A tubes.

[stingray_65]

GRRRRR!

I have hit up every person I knew with a tube amp this weekend and collected every tube I need.....

except a 5y3 recto

so here I still wait to fire this pup up.

My son,whom this amp is built for, reminded me to be patient! LOL!
thats been out of my lips more times than you can imagine during this project to him....

....all the time the glue joints dry, all the times I spent making various face plates on the mill, so on and so on, now he's usuing my own lectures against me.


one good thing did happen for the amp this weekend was I scored 3 7/8 yards of dk. olive snake skin tolex for $7.00 at a fabric store. a custom order that was never paid for stitting on the close out table waiting for me to stumble across it.

it wasn't my first choice for covering, but my 19yo son thinks it is so friggin cool!

good for him

we named the amp this weekend too "the Soul Shaker"

bought some black/silver speaker cloth and embroidered the soul shaker logo onto it.

we also got to try out the speaker bin ( we built this as a head and bin) on my buddy's silvertone amp. WOW! Ted Weber is a genius!

so thank you all for your suggestions, experience and knowledge.

Ray