Show us your flea-watts amps!

[Thefamous]

No EL34's, just one 12AX7 and two 6BQ5. Choke and a large polypropylene motor run capacitor underneath. Two 10 watt Transcendar OPT and a Hammond 370FX mains transformer.

6BQ5 is the same as an EL34, isn’t it? Maybe I’m mixing up tubes. Sometimes I remember the European numbers and sometimes the American ones.

I have been playing with using 6N2P instead of 12AX7. Almost the same characteristics, slightly different pin out. But lots of NOS available for cheap from Eastern Europe. Used some in a phono preamp and was quite pleased.

 

[AmadeusMozart]

6BQ5 is the same as an EL34, isn’t it? Maybe I’m mixing up tubes. Sometimes I remember the European numbers and sometimes the American ones.

I have been playing with using 6N2P instead of 12AX7. Almost the same characteristics, slightly different pin out. But lots of NOS available for cheap from Eastern Europe. Used some in a phono preamp and was quite pleased.

Hello, 6BQ5 is not the same as EL34.
6BQ5 = EL84 -> 12Watt anode dissipation
7189 similar but 14 watt anode dissipation
Russian - similar as 7189 (14 watt anode dissipation)
6N14P 500 to 1500 hours life expectancy depending on manufacturer
6N14P-E 5000 hours life expectancy
6N14P-EV rugged version, can have 10 000 hours life expectancy

The 14 watt versions will work for a 12 watt version but not the other way round.

The new amplifier will be using a 2c51 instead of the 12AX7 as driver. Totally different pinout.
Better characteristics and often used in headphone amplifiers and DAC's. 2C51 similar to 396A, 5670, 6N3P (6N3P-E, 6N3P-EV).

If using tube coolers you might get 5 ~ 10 x the life out of a tube (Pearl or IERC 6025B NOS). Function over looks?

 

[Thefamous]

Hello, 6BQ5 is not the same as EL34.
6BQ5 = EL84 -> 12Watt anode dissipation
7189 similar but 14 watt anode dissipation
Russian - similar as 7189 (14 watt anode dissipation)
6N14P 500 to 1500 hours life expectancy depending on manufacturer
6N14P-E 5000 hours life expectancy
6N14P-EV rugged version, can have 10 000 hours life expectancy

The 14 watt versions will work for a 12 watt version but not the other way round.

The new amplifier will be using a 2c51 instead of the 12AX7 as driver. Totally different pinout.
Better characteristics and often used in headphone amplifiers and DAC's. 2C51 similar to 396A, 5670, 6N3P (6N3P-E, 6N3P-EV).

If using tube coolers you might get 5 ~ 10 x the life out of a tube (Pearl or IERC 6025B NOS). Function over looks?

EL84. Thanks. I thought I might be mixing them up.

That little amp looks nice. I’m sure it’ll sound sweet when you're done.

 

[setup1]

My interpretation of a Darling amp. 750 milliwatts per channel.

 

[Redboy]

My interpretation of a Darling amp. 750 milliwatts per channel.

Lovely! What are you going to do with all that power?!?

 

[setup1]

Lovely! What are you going to do with all that power?!?

Thanks!

750mWpc is for late night listening...

1250 mWpc Simple 46 with Noguchi FM6WS for medium levels

3500 mWpc Radiotron SE2A3 rocks the man cave

 

[AmadeusMozart]

Thanks!

750mWpc is for late night listening...

1250 mWpc Simple 46 with Noguchi FM6WS for medium levels

3500 mWpc Radiotron SE2A3 rocks the man cave

Very nice!

Are these the aluminum Hammond chassis and if so how do they hold up under all the weight of the transformers? I've got some bad experience with 1mm (0.04") aluminum chassis in days long gone past but todays aluminum may be stronger than what was available at the time. I've been looking at the Hammond chassis and I would go steel but the size I like is not available.

 

[setup1]

Very nice!

Are these the aluminum Hammond chassis and if so how do they hold up under all the weight of the transformers? I've got some bad experience with 1mm (0.04") aluminum chassis in days long gone past but todays aluminum may be stronger than what was available at the time. I've been looking at the Hammond chassis and I would go steel but the size I like is not available.

With the size of iron I used in these two projects, the regular Hammond aluminum chassis was adequate. With more substantial iron, I would've used heavier gauge aluminum plates.

 

[AmadeusMozart]

Thanks, I like things sturdy - the flea amp shown previously used 1/8" aluminum because that was what the fabricator had at hand. I would have liked 5/64" instead.

The standard Hammond 6"x10" steel is on the small side for some bulky transformers, a choke plus three miniature (B9A) tubes and one octal delay relay. Without the choke I would have managed but I find the next size up (in steel) too much of a jump up in size (8" x 12"). In aluminum there are also the 7" x 11" and the 8" x 10" and either will work.

 

[nerdorama]

A reworked RCA console amp. Just running today. I used a circuit recommended by Kegger several years ago for another owner of this amp. My build thread is here:
https://audiokarma.org/forums/index.php?threads/rca-rs-199b-console-amp.902779/#post-13557954

 

[tonya4921]

My 46 amp using tango xe-20s iron

 

[mroboto]

Slightly Modded Douk 6P3P (*2) 6N9P (*1) 5Z4 (*1)

 

[setup1]

My 46 amp using tango xe-20s iron
View attachment 1786229

Congrats, Tony!

 

[tonya4921]

Thanks, Joseph!

 

[random_noise]

wow some really nice amps are being posted in here

here is a future project of mine, got these "as is", maybe i'll do a point to point version of it



edit:

I'm working on a pair of SEUL EL84 monoblocks now, but progress has been... slow.

that's the most beautiful amp i've ever seen,
may i ask for a schematic please?

 

[AmadeusMozart]

With the size of iron I used in these two projects, the regular Hammond aluminum chassis was adequate. With more substantial iron, I would've used heavier gauge aluminum plates.

This week my order arrived with the Hammond 1444-12825 aluminum chassis (12" x 8" x 2.5"). Unfortunately the top is bend downwards in the center by about 1/16" which make the transfomers lean towards each other. Pushing the top upwards from the bottom does not rectify this, they've set the corners just less than 90 degrees. Also the bottom is not lining up properly in the corners. Quite disappointed and I regret buying it.

I also have my doubts that I would have had a more positive experience with a steel chassis. I've let the vendor know and hopefully they'll take it up with Hammond as it is just not good enough.

 

[setup1]

IME, 2.5" height only works with a long and narrow proportion. I limit the height to 2" (like the above) if the chassis is "squarish".

 

[Falstaff]

I just purchased this on the bay. It's a portable/console record player amp using two 50EH5 with a 35W4 rectifier. Hot chasis so will have to add an isolation transformer and as long as I am at it a three prong plug socket, a fuse, an on/off switch, speaker connectors and maybe a pilot light. Is working as is and puts out just about 1.5 WPC.

 

[Lavane]

Im not familiar with the 50EH5. Does it have a triode and pentode in one bottle?

 

[derekva]

My "Shelter In Place" 1626 Darling Amp using Sony TC-500a iron (still need to build a chassis to house it and maybe swap out the 156R choke for a Triad C-7X to quiet it down a bit more):



Sounds great at a whopping 0.75WPC!