Musica Bella Single Ended EL84 amplifier

Response Audio · December 04, 2014, 09:13:17 AM

Here is a quick shot of the single EL84 amplifier. Chassis was started a little over a year ago and put on the back burner for a while.

The choke filtered power supply is tube and based on the 5U4 rectifier. High quality polypropylene capacitors are used in the first filter stage before going through the choke then a Mundorf electrolytic bypassed with a quality film cap.

Inside you will find a Mod Cap Oil Cap for the coupling capacitors and film shunt capacitors. Internal wiring will be Cryogenically Treated Silver Plated Stranded Copper. Front panel will house two illuminated analog ammeters monitoring each EL84 output tube.

Matching LeAnna preamp models are also available. There is also a SET 300B stereo amp available.

More pictures will be posted as this piece is finished.

Response Audio · December 08, 2014, 08:00:25 AM

Here is a shot of a matching preamp still under construction. zvisit this link to find out more about this custom LeAnna EV Plus.
http://www.responseaudiony.com/customshop.htm

Response Audio · December 12, 2014, 08:53:54 AM

Sorry about the poor picture quality. Havent had time to get the good camera out.
This custom is completed and ready to go. See all the details at http://www.responseaudiony.com/customshop.htm

And here is the matching Single Ended EL84 amp. Not yet done.

Response Audio · December 21, 2014, 06:31:14 PM

Glorious sound. I was going to keep this setup for myself but someone contacted me today wanting both pieces. Okay, time to build the 300B version

The new custom LeAnna preamp I am building now has tube tone controls so I think I will build the 300B amp and preamp as a matching set.

sleepyguy24 · December 24, 2014, 08:15:30 AM

Very very nice work.

Is the SE EL84 amplifier one of those lower powered flea watt amps you discussed before? What do the meters in the front specify?

Response Audio · December 24, 2014, 08:57:12 AM

Hello Sleepy and Merry Christmas to you and yours.

Yes, this is one of the amps that will be part of the flea watts previously discussed.

The meters are for current readings on the EL84 tube. However, the current never changes as there is a current sink circuit installed at the EL84 cathodes.

Response Audio · January 04, 2015, 10:41:32 AM

Both pieces officially sold. I'm really gonna miss this amp.

Now, rather than the 300B, I first want to do the PPE34. This one uses 2 EL84's in parallel running in pentode for 10 watts per channel.
I want to come up with a really unique chassis design for this one. Off the wall.

The 300B amp will follow. The chassis is built but have some cutting to do yet after I get the output transformers and then get painted gloss white.

Response Audio · January 17, 2015, 06:55:01 AM

Here is a quickk shot of the chassis under construction for the 10 watt Parallel Pentode EL84 amplifier mentioned above. More details on whats going into this one can be seen at http://www.responseaudiony.com/customshop.htm

Triode Pete · January 17, 2015, 06:56:24 AM

Quote from: Response Audio on January 17, 2015, 06:55:01 AM
Here is a quickk shot of the chassis under construction for the 10 watt Parallel Pentode EL84 amplifier mentioned above. More details on whats going into this one can be seen at http://www.responseaudiony.com/customshop.htm

Very nice!!!

Response Audio · January 17, 2015, 06:58:53 AM

Thank you Pete. The chassis is 1/8" Birdseye Maple over Baltic Birch. The top and bottom pieces are 1/2" solid Cherry painted satin black.

StereoNut · January 17, 2015, 07:17:24 AM

Absolutely LOVE the birds-eye maple!!!

rpf · January 17, 2015, 10:18:35 AM

Beautiful!

How about a KT66 amp?

Response Audio · January 17, 2015, 10:39:54 AM

QuoteBeautiful

!

Thank you.

QuoteHow about a KT66 amp?

Whenever you're ready

Response Audio · January 17, 2015, 11:09:51 AM

Hhmmm.......Maybe I will build this one as a 6L6/KT66 amp. I have planned on the 807 tube but there are adapters that can be used to use the 807 in place of the 6L6. This would provide more versatility over building with the odd 807 tube sockets.

Response Audio · January 18, 2015, 08:12:55 AM

After looking over the chassis above and the design used for the 6L6/KT66 version, I will not build it into this chassis. We will stick with the PPE EL84.

I will start on a new, larger chassis that will be able to run EL34, 6L6, KT66, 6550, KT88 tubes. This requires a larger chassis to be able to house the larger, choke input power supply used in this model. I like the choke input design as it allows the use of one of my favorite rectifiers, the 274B by Sophia Electric.

I am going to build a more standard 'vintage' style chassis for this amp with wither cherry or some of the Birdseye Maple I have.