Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: DummyLoad on January 29, 2011, 01:13:00 am

Title: HMs Lucky7
Post by: DummyLoad on January 29, 2011, 01:13:00 am: just doodling again... this is a spin of the burger king amp -- with mostly more popular tubes, although i must confess i don't know how common 6AB4s are/were.

criteria:

use 7 pin miniatures - gots a buncha_em & sockets_a_plenty.
use 7 tubes.
at least 7 WRMS output.

like a slot machine payoff: 7-7-7 :grin:

reference below is likely old hat for most of you.

6136/7543 - lo micro./lo hum 6AU6
6AV6 - 1/2 12AX7 sub 6AT6 for slightly less gain.
6AB4 - 1/2 12AT7
6005 - mil./comm. grade 6AQ5

have everything but the 6AB4s - anyone have any 4 sale? :wink:

hybrid of a deluxe/matchless w/ a LTPI.

bias should be around 70mA for both tubes w/ ~~15V on the cathodes for ~~10W/tube Pdiss @ idle. at least i think it is... if i tossed the darts proper.

i have not built this but in time i plan to. i have other projects in the works. fishing for sluckey & hoping he bites - the topic of a concept of an all 7pin tube amp came up some time ago...
:wink:

as always, comments & suggestions welcomed.

--ISO

sorted 7pin miniature types.

6AV6 = 1/2 12AX7
6AB4 = 1/2 12AT7
6C4 = 1/2 12AU7
6AT6 = 1/2 6SL7?

6AM4 u 85 gm 9800 rp 8700
6AN4 u 70 gm 10000 rp
6AQ4 u 100 gm 8500 rp 12000 <--- forza massimo !muah!
6AQ6 u 70 gm 1200 rp 58000 <--- 1/2 6SL7?
6BC4 u 48 gm 10000 rp 4800
6BF6 u 16 gm 1900 rp 8500
6BK6 u 100 gm 1600 rp 62500 <--- 1/2 12AX7
6BN4 u 43 gm 6800 rp 6300
6BT6 u 70 gm 1200 rp 58000 <--- 1/2 6SL7?
6BU6 u 16 gm 1900 rp 8500
6C4W u 17 gm 2200 rp 7700 <--- 1/2 12AU7
6DR4 u 100 gm 1600 rp 62500 <--- 1/2 12AX7
6DZ4 u 14 gm 6700 rp 2000
6ER5 u 80 gm 10500 rp 8500
6ES5 u 75 gm 9000 rp 8000
6FH5 u 50 gm 9000 rp 5600
6FQ5 u 75 gm 12000 rp 6300 <--- semi-remote c/o
6FY5 u 70 gm 13000 rp <--- remote c/o
6GW5 u 70 gm 15000 rp 5800
6HA5 u 72 gm 14500 rp
6J4 u 55 gm 12000 rp 4500
6N4 u 32 gm 6000 rp 5400
6T4 u 13 gm 7000 rp 1860
Title: Re: HMs Lucky7
Post by: jeff on January 29, 2011, 02:34:42 pm: If you use 2 50uF caps in parallel instead of one of the 100uF then you'd have 7 filter caps. Now you need to find a 7ohm speaker.
:grin:
Title: Re: HMs Lucky7
Post by: stingray_65 on January 29, 2011, 04:15:25 pm: sent PM

Ray
Title: Re: HMs Lucky7
Post by: DummyLoad on January 29, 2011, 05:26:56 pm: Quote from: jeff on January 29, 2011, 02:34:42 pm
If you use 2 50uF caps in parallel instead of one of the 100uF then you'd have 7 filter caps. Now you need to find a 7ohm speaker.
:grin:

or, it is possible to use single 6J6 for LTPI and use 10k Zpri OT. for:

6 tubes
6 filters
6 watts

6669 to replace 6005/6AQ5
6664 to replace 6135/7543/6AU6

that a lot of 6-6-6es... almost an evil #.

:angel

665 amps: almost evil amplification.
Title: Re: HMs Lucky7
Post by: stingray_65 on January 29, 2011, 08:41:43 pm: If it makes you feel any better, I'll test the 6AB4's on my Eico 666 :angel
Title: Re: HMs Lucky7
Post by: DummyLoad on January 29, 2011, 10:02:45 pm: Quote from: stingray_65 on January 29, 2011, 08:41:43 pm
If it makes you feel any better, I'll test the 6AB4's on my Eico 666 :angel

pure evil!! do eeet~!

:angel
Title: Re: HMs Lucky7
Post by: PRR on January 29, 2011, 11:54:21 pm: > a lot of 6-6-6es...

You could build an amp using only 6-pin tubes. 42=6F6 on six legs. 25N6/25B5. 77 can be your voltage amp.
Title: Re: HMs Lucky7
Post by: DummyLoad on January 30, 2011, 01:19:59 am: You could build an amp using only 6-pin tubes.

ya kno, buttery and i kicked that idea around a some time ago. our antique radio dealer told us that most the numbered tubes of that era were of prized collector value now to keep those older radios going. in other words: he didn't really want to sell us any to build a guitar amp. i can respect that.

we did bounce around the idea of building a guitar amp using military surplus metal clad tubes (6j7, 6SF5, 6SC7, 6l6, etc..) since he had an abundance of them, but it was only as a passing joke and the joke was: let's see if the roadies can tear this one up!

come to think of it, this amp i posted could be built with military_metal_clad valves. hmmm...a high-gain rock-n-roll amp tribute to rosie the riveter.

--ISO
Title: Re: HMs Lucky7
Post by: RicharD on January 30, 2011, 09:25:10 am: I'm ashamed to say I haven't turned on an amplifier or my soldering iron so far this year. I did clean the lab yesterday. Bulk trash collection on Monday. A bit of a motivator. I need to get back in the swing. Good to know ISO is picking up my slack.
Title: Re: HMs Lucky7
Post by: OldHouseScott on January 30, 2011, 02:17:24 pm: Quote
665 amps: almost evil amplification

Haha! Sounds like a Spinal Tap reference!
Title: Re: HMs Lucky7
Post by: DummyLoad on January 31, 2011, 10:06:46 pm: Quote from: stingray_65 on January 29, 2011, 04:15:25 pm
sent PM

Ray

thanks ray! you're a good egg. :grin:
Title: Re: HMs Lucky7
Post by: DummyLoad on January 31, 2011, 10:07:32 pm: Quote from: Butterylicious on January 30, 2011, 09:25:10 am
I'm ashamed to say I haven't turned on an amplifier or my soldering iron so far this year. I did clean the lab yesterday. Bulk trash collection on Monday. A bit of a motivator. I need to get back in the swing. Good to know ISO is picking up my slack.

:sad:

:smiley: