Show us your flea-watts amps!

[BinaryMike]

At 1.5 watts it could make for a nice headphone amp too?

That seems likely. Bolide should be intrinsically free of hum because the B+ rail is regulated and supplies the series-wired heaters as well. It does require a negative rail too, but the load on this rail is minimal which makes it easy to filter.

 

[Tinkerbelle]

This is a Motorola HS-1260 console unit using 50HN5 OP tubes, SE for probably ~3.5W

Yes, it was without a PT but I added an isolation transformer and fuse to it.

 

[kward]

The Bolide low-voltage SET breadboard develops about 1.5W output using $4 worth of tubes from the dollar bin at ESRC

Mike seems to always have something inexpensive and tasty cooking up in his lab!

 

[random_noise]

2x5w class A pp el84 e88cc naked

 

[Lavane]

That seems likely. Bolide should be intrinsically free of hum because the B+ rail is regulated and supplies the series-wired heaters as well. It does require a negative rail too, but the load on this rail is minimal which makes it easy to filter.

Everything would fit nicely on a PCB.

 

[macgolf]

Single ended Rotel EL84 receiver.

View attachment 1047431

Is that a FAX-150? Until mine returns from the shop, I do have this SE EL84. Pics taken day it arrived in July with stock tubes. The blue LED's aren't nearly as annoying from my seated position but the chrome is hard to keep clean. Wanted 2 inputs and this fit the bill for some fun! Listening to it now with 6P14P-K & RCA 12AX7A.

 

[Poultrygeist]

Is that a FAX-150? Until mine returns from the shop, I do have this SE EL84. Pics taken day it arrived in July with stock tubes. The blue LED's aren't nearly as annoying from my seated position but the chrome is hard to keep clean. Wanted 2 inputs and this fit the bill for some fun! Listening to it now with 6P14P-K & RCA 12AX7A.
View attachment 1048613

yes - Martel and Roland merged to become Rotel

 

[70'sredo]

I guess this qualifies. 1.5 WPC? Marketed by AMD in the early 60's. Japanese construction. These pop up on the auction site under different brand names.
AMD is still around selling processor chips. Sounds very nice. I have this running out to the speakers on a mid 60's RCA stereo phonograph which is Solid state and is all germaniuim. I just like the way the speakers sound, and I've been playing around with the phonograph for several weeks.

 

[Blasty]

Here are some pictures of my DIY 3-Watt mono blocks taken at my workbench the moment I completed the second unit. Even with a lazy twist on the heater wires only, the background is silent due to careful layout. I use these to drive Klipsch La Scalas with more than enough authority!

 

[opa1]

New Flea. SE Triode Mode 5V4/6SL7/6V6.

 

[knockbill]

• 
  
• I like it!!! Reminds me of my SE 6AQ5/6SL7/6BW4 amp... its on here someplace!
• Here's a newer pic,, as it is today... I found Schumacher OPTs at a radio show...

 

[Omegaman]

Here is my Japanese hand built Morikawa 2A3 SET amp with TANGO transformers


Runs at 100vac

 

[GordonW]

I never got around to posting these in this thread- two 6V6SE amps I built from scratch.

First one, is using an Eico HF12 PT and Curtis-Mathes OPTs:

Second one is the same circuit, just using a Wollensak reel-to-reel PT, and a pair of Magnavox SE output transformers, from the AMP150 type amps:

Both of these are using 12AU7s as preamp and amp drivers. About 11dB of feedback.

And no- one of the pictures is NOT reversed. For whatever reason, I wound up doing one of them in "mirror image" with the controls, compared to the other.I think it was because of how the power supply transformer and power supply caps wound up arranged in the amp- keeping the wiring for the power switch as short as possible...


Also- here is one I don't think I ever posted here before- a 6V6 SE integrated amp with phono stage, that I built for audiobeer.



This one was based on the amp parts (transformers, knobs, trim pieces, etc) from a Zenith portable record player that audiobeer sent to me. I painted the top to match the original cream-white color of the inside of the record player (the turntable plinth and such), and the wood side trim pieces were painted to match the original "Samsonite brown" color that was on the outside of the turntable cabinet. The front is covered with some of the original gold-thread-infused grill cloth from the front of the turntable, and the gold-color metal trim on the top and bottom of the front panel is cut down from the original grill trim on the turntable.



Those are the original knobs and logo plate from the turntable too. The knobs were numbered from 0 to 8- for the source selector, they have a travel range of 1-4, for the volume control, they are full-rotation from 0-8, and for the power switch- I took the original pot-with-rotary-power-switch, removed the pot terminals, made up a stop so that the switch only moved far enough to go on-off, and the knob goes from 0-1 (off-on, as in binary). So, the original knob markings actually "mean something" on each knob...



It's using the power transformers from both the turntable itself, and the additional add-on amp/speaker that came with it (early stereo- add on speaker with amp that connected with an RCA cable to the back of the original turntable), with 12AX7 phono stage tubes (Dynaco PAS phono circuit), and the same preamp/amp circuit, basically, as the other two SE amps before (12AU7/6V6).

Regards,
Gordon.

 

[JohnMac]

Wow Gordon, what a unique dressing on that one! Looks like something Magnavox should have offered back in the day.

Oh, and not to mention the circuitry.

 

[AdamAnt316]

Built this little mono amp from a Popular Electronics article for a high school science fair project:

Uses a pair of 60FX5 tubes in push-pull for around 3 watts. Extremely simple circuit, with no capacitors in the audio chain, and a transformer-coupled input. Oughta build a second one at some point. Here's the diagram of the circuit:

 

[prelius]

Have not done this in a while, so here it goes...

A 6V6 SE, based on Kegger's schematics, with smear of "artistic pretense". I called it "Sweet Obsoletion"... Made out of recycled computer parts. Hum-free. About 4 watts per channel.

Cheers, Paul.

 

[linuxslate]

Definitely flea power, and my first home-made tube amp:

Still undergoing some development, but it does work.

Thread here:
http://audiokarma.org/forums/index....re-p_p-amp-talk-me-out-of-building-it.847654/

It is intended as a small PC speaker amplifier.

Push-Pull, uses 5902 subminiature tubes. It runs from a 12V power brick.

I'm currently building a Lexan and metal grid cover.

Basic design by Bruce Brown, and published in the April 2011 copy of AudioXpress, but with modern power supplies.

 

[mroboto]

 

[Poultrygeist]

Here is my Japanese hand built Morikawa 2A3 SET amp with TANGO transformers
View attachment 1373329
View attachment 1373330
Runs at 100vac

Looks very much like the Japanese Sun amp.

 

[Poultrygeist]

The 4 watt EL84 SE on top is a Dennis Had Magnavox redux.