New EL84 based amp

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Tyson

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New EL84 based amp
« on: 19 Jan 2020, 05:53 am »
Picked this up from VTA audio (tubes4hifi.com) and gotta say this thing is dead sexy:










Sound is shockingly good for an amp under $1k.  It reminds me of the see-through clarity of my Korneff Type 45 SET amp, but with more punch and power.  Clear, smooth, beautiful, punchy.  That pretty much sums it up.  Paired with my hotrodded Klipsch Forte III speakers, it's the kind of sound that makes me want to go through ALL my recordings to see how they sound.  Because everything sounds so goooooooooood. 

Listening to JS Ondara right now and his voice is just heartbreaking. 

Edit to add web page link - http://tubes4hifi.com/ST35.htm

EDIT:

With the smaller case that the prototype used, I had to punch some holes in the top to vent the tubes properly.  A buddy of mine has a metal shop, and this is what we came up with:



« Last Edit: 15 Nov 2020, 06:53 pm by Tyson »

Freo-1

Re: New EL84 based amp
« Reply #1 on: 19 Jan 2020, 05:24 pm »
Nice score, Tyson.   :thumb:


The EL84 is easily one of my favorite tubes for audio.  They dd many things right. 


Looking forward to your more detailed impressions with the amp. 

Scott F.

Re: New EL84 based amp
« Reply #2 on: 19 Jan 2020, 05:32 pm »
That's cool. The EL84 is one of my favorite tubes. Best part is you can get a decent sound quad for puny bucks in comparison to the other power tubes. That and there are TONS of vintage tubes to choose from and they aren't much money either.

I still use a hot-rodded HH Scott 299 and a Jolida 102B with some better coupling caps. Love the sound of both.

Nice score  :thumb:

jmolsberg

Re: New EL84 based amp
« Reply #3 on: 19 Jan 2020, 08:49 pm »
Great LQQking amp!

Tomy2Tone

Re: New EL84 based amp
« Reply #4 on: 19 Jan 2020, 09:07 pm »
Is this essentially your amp without the volume control?

http://www.ankaudiokits.com/2/l3el84pp.html

Tyson

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Re: New EL84 based amp
« Reply #5 on: 20 Jan 2020, 06:54 am »
Is this essentially your amp without the volume control?

http://www.ankaudiokits.com/2/l3el84pp.html

Looks like the same board, but different power transformer and output transformers as far as I can see.  And yes, mine has no volume or input switching (per my request) 

The circuit seems to be a modern day take on the old Scott 299 mentioned earlier - it's a 6BL8 tube driving a pair of EL84's for output.  The very interesting thing about the 6BL8 is it's a triode and pentode in one.  So the triode part of the tube does the phase splitting and the pentode portion drives the EL84's. 

Whatever they are doing, it's working!  This is a very quick sounding amp, really letting the music boogie, but without losing that amazing midrange that great tube amps are capable of.

FullRangeMan

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Re: New EL84 based amp
« Reply #6 on: 20 Jan 2020, 07:12 am »
This 6BL8 compactron are great, just 1 dolar in Russia:
https://www.gstube.com/catalog/?key=6%D41%CF&submit=Find
« Last Edit: 20 Jan 2020, 08:12 am by FullRangeMan »

veloceleste

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Re: New EL84 based amp
« Reply #7 on: 20 Jan 2020, 11:23 am »
Love my Quicksilver Integrated that uses four el84 per channel driven by 12dw7 which is a combined 12ax7 and 12au7. Paired with Klipsch Chorus II or Bryston Mini T's it sounds great although a little underpowered for the Bryston speakers.

mick wolfe

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Re: New EL84 based amp
« Reply #8 on: 20 Jan 2020, 05:59 pm »
Tyson....is that EL84 based amp a custom build? Can't find any info on their (VTA) site  :scratch:

Tyson

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Re: New EL84 based amp
« Reply #9 on: 20 Jan 2020, 06:49 pm »
Tyson....is that EL84 based amp a custom build? Can't find any info on their (VTA) site  :scratch:

http://tubes4hifi.com/ST35.htm

I'll update my first post to add it.

Tyson

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Re: New EL84 based amp
« Reply #10 on: 20 Jan 2020, 06:51 pm »
Love my Quicksilver Integrated that uses four el84 per channel driven by 12dw7 which is a combined 12ax7 and 12au7. Paired with Klipsch Chorus II or Bryston Mini T's it sounds great although a little underpowered for the Bryston speakers.

Yes the EL84 seems like an awesome tube if used within it's power limitations.  Although 17 watts is actually a lot higher than the 8 watt 300B I was using before, haha.

opnly bafld

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Re: New EL84 based amp
« Reply #11 on: 20 Jan 2020, 07:13 pm »
 8)

Picture of the back please.

mick wolfe

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Re: New EL84 based amp
« Reply #12 on: 20 Jan 2020, 07:40 pm »

genjamon

Re: New EL84 based amp
« Reply #13 on: 20 Jan 2020, 07:43 pm »
What are they economizing on to make it half the cost of the Audio Note kit that it's based on?  Looks like the board is still the Audio Note kit board?

Tyson

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Re: New EL84 based amp
« Reply #14 on: 20 Jan 2020, 07:48 pm »
What are they economizing on to make it half the cost of the Audio Note kit that it's based on?  Looks like the board is still the Audio Note kit board?

Looks to me like the power transformer and output transformers, and likely the output caps too.

Tyson

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Re: New EL84 based amp
« Reply #15 on: 20 Jan 2020, 07:49 pm »
8)

Picture of the back please.


Sure thing, I'll add pics of the amp with the cover on as well as the back panel. 

The back panel is just stock parts, I wanted to hear it "stock" for a couple weeks before doing any modding.  Even bone stock (and with stock tubes like the Electroharmonix EL84) it sounds incredible. 

Pretty soon I'll whip out the soldering gun & put premium parts on it for the RCA connectors, the binding posts, the IEC connector, the coupling caps and the input/output internal wiring. 

xoundmind

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Re: New EL84 based amp
« Reply #16 on: 20 Jan 2020, 08:02 pm »
First time poster and proud owner of one of Roy’s phono stages (PH-14):

This is a pure power amp or can be configured to as integrated?

jmolsberg

Re: New EL84 based amp
« Reply #17 on: 21 Jan 2020, 05:19 pm »
please keep us posted with your experiences on this little amp. I say everyone can use an EL84 tube amp in their stable (:
unfortunately I don't have one ):

Tyson

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Re: New EL84 based amp
« Reply #18 on: 23 Jan 2020, 12:37 am »
You might be asking, "Did you replace the IEC with a pure copper, gold plated Furutech today?"  Why yes, yes I did.

You might also be asking "Did you replace those brass generic binding posts with pure copper ETI Research cable pods today?"  Why yes, yes I did:



You probably are asking, "Wait, are those pure copper Miflex caps on that board now?"  Why yes, yes they are.

And you might want to know "Hey, did you replace the output wire with OCC copper/teflon wire?"  Yep.

Finally, "Did you dump the stock EH EL84 and replace them with NOS Russian military tubes?"  Oh yeah.


Tomy2Tone

Re: New EL84 based amp
« Reply #19 on: 23 Jan 2020, 12:47 am »
Was the Furutech iec inlet a straight swap or do you have to widen the opening at all?

This looks like a great amp to play around with and for the price a no brainer if you got the speakers for it.

Look forward to your thoughts after everything has settled in.