The Beginning and The End! New Alan Eaton 45 SET Amp in progress for 3 HO's!

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thetakeout

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AVSFan

I have no clue on the preamp.  One that sounds good and doesn't cost a fortune. 

I want to hear a passive, a tube & a solid-state and just learn. 

I know I am a fan of 12SL7/6SL7 for input tubes.  That much I do know.


Kray

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AVSFan

I have no clue on the preamp.  One that sounds good and doesn't cost a fortune. 

I want to hear a passive, a tube & a solid-state and just learn. 

I know I am a fan of 12SL7/6SL7 for input tubes.  That much I do know.

I’m using a Khozmo Acoustic Passive pre with amp, while my tube based matching preamp is being built and pleasantly surprised.

One thing to learn is impedance and sensitively matching for your pre and amp. Example I had a great TAD-150 tube pre based on 12AT7/12AX7 and it caused too much hum with my amp. It worked beautifully with other amps but not my 45 Yamamoto based amp. Oliver said the Yamamoto doesn’t need much gain at all (if any) and 6db was about max he recommended. So going with a 6AH4 based preamp

roscoe65

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Very good point about sensitivity matching.  Noise or hum that is barely audible on 90dB speakers may be objectionable with 96dB speakers.  My Dennis Had amp both needs a preamp and is not 100% silent.  Consequently it works better with medium-high efficiency speakers (20 wpc and 90dB is a good combo in my room).  On the other hand, my Oliver Sayes/FI 421A SET has an input sensitivity of 0.65V and is D-E-A-D quiet.  I only use a unity gain tube preamp for the remote control.  My DAC puts out about 2.5V, so there is not only no need for gain there is no room for it.

JTF

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I have no clue on the preamp.  One that sounds good and doesn't cost a fortune. 

I want to hear a passive, a tube & a solid-state and just learn. 

I know it's Schiit but the Freya+ does all of those things in a single unit. You can switch between passive, jfet and tube buffer. I just sold one, I had it for about 9 months. Really good for the price.

AvsFan

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Alan informed me that he is breaking in my amp all day today. Making sure that everything is working the way it's supposed to before shipping tomorrow.

jmolsberg


AvsFan

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Last picture before shipping. I went with the round knobs.




Kray

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Looking good Jeff

These 45 amps are so beautifully simple. Especially when you see the guts and realize the beauty in the circuit.

JTF

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Last picture before shipping. I went with the round knobs.

Looks good AvsFan. I saw your amp in person this morning. I drove up to his workshop to get a nick in the paint touched up and to pick up a pair of KG4s. Incidently, he just sent me a video of your amp playing on another pair of Klipsch, I let him know he sent it to the wrong person.

AvsFan

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Looks good AvsFan. I saw your amp in person this morning. I drove up to his workshop to get a nick in the paint touched up and to pick up a pair of KG4s. Incidently, he just sent me a video of your amp playing on another pair of Klipsch, I let him know he sent it to the wrong person.

As long as it sounded good to you.  :D

roscoe65

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I’m jumping back onto the 45 SET amp bandwagon.  Years ago (ca. 1997 or so) I owned a direct coupled 45 amp and foolishly let it go.  With all the talk about the Eaton 45 amp and Super 3 HO Monitors, I decided to jump back in.

I bought a Korneff-style 45 SET built by Oliver Sayes using the same iron set as Eaton.  It is a two stage amp rather than the SRPP of Eaton so it needs a higher gain preamp which I can fortunately provide.  It will be interesting to hear how this compares with memories of over 20 years ago.

StevenZ

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Do you guys have any complaints about stereo separation?  Another amp builder has said that shared filament heater for his single chassis amps will only provide about 40db of separation.  Any complaints or input?

BTW, mine is shipping from Alan today.

roscoe65

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That sounds interesting.  Not sure if it is true.

I fired up the Korneff 45 clone.  The Korneff uses a 6J5 driver (1/2 6SN7) instead of the SRPP 6SN7 of the Eaton amp.  It has one less gain stage and it shows.  My unity gain preamp could not drive it to anywhere near full power.  I will need to go active.

Docere

Do you guys have any complaints about stereo separation?  Another amp builder has said that shared filament heater for his single chassis amps will only provide about 40db of separation.  Any complaints or input?

BTW, mine is shipping from Alan today.

So, the heaters of for tubes in both channels are run off the same secondary winding. I don’t do that and have not compared to using separate windings. Remember that these are indirectly heated tubes... is it being suggested there is some coupling of signal between channels through the heaters? I suspect additional contributors...

Now, if tubes were sharing a local PS capacitor or, if memory serves, cathode circuit between channels that was popularised by some some builders a decade or so ago or mediocre grounding.

Anyway, some builders argue that stereo separation is over-rated or that extreme separation sounds artificial. I suspect it comes down to personal preference.

Docere

Okay. I just saw the info given on the 'Haven. Armed with more info: yes, in directly heated tubes (like Type 45s), filaments sharing a single secondary winding would limit channel separation. Filaments in DHTs are part of the signal path.

Whether this is a feature or a mistake? Without hearing it, most will suggest the later. It is not typical and I'd not compromise a build over an extra secondary winding and pot - not many builders would (some cheap Chinese manufacturers excepted) - so perhaps the crafter has made a conscious choice based on his sonic preferences? Listen and decide for yourself.

StevenZ

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Being that none of the users who have one have complained I imagine it's not noticeable and may be a design preference of Alan's. His amps are selling well and continue to go for good money. He's built a heck of a following so he must be doing something right.


thetakeout

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Docere & StevenZ

The Eaton amps sound fantastic.  I have heard them in mono block and single chassis form.  No complaints over here. StevenZ.  Did the local builder do a tear down?  How did his commentary come about?



Roscoe.  What is your unity gain preamp?

roscoe65

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I’m using the pre-out of a Red Wine Audio Signature 16.  Unfortunately I can’t find a way to work it into my systems. 

AvsFan

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Well unfortunately the end came sooner than I expected. The Eaton 45 had a major buzz issue in both channels. It increased with turning up the volume. It was bad. And I knew from the get go that it had to be a volume pot issue. I wasted a lot of time trying to see if it was other issues first just to rule out every possibility. But I knew it couldn't be system related because all my other electronics and amps have 0 noise. So sent it back to Alan and sure enough, it was mislabeled volume pots. That was the culprit. But I has already gotten a refund by then and had my Omega's hooked up to my Digital Amplifier Company amps. Which sounded spectacular! Golden Cherry Monoblocks. And at 6ohms, they are putting out around hefty 270 watts per channel. The Omega's love them. So the idea that only low watt tube amps make Omega's sing. Absolutely not true. Not arguing the fact that low powered tube amps sound good with Omega's, because they do, I am just simply stating a fact that it's not the only option. It all boils down to the QUALITY and design of the amp, not the wattage.


rollo

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  • Rollo Audio Consulting -
  Where does one contact Alan Eaton. Glow in the dark site ??

thanks
charles