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1st Tube Amp - What to build?

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I'm interested in building my first Class A tube amp to drive full range audio speakers. I've built several solid state amps, and interested in tube experimentation.

Question: Is there a great reference design for pure class A, 3-10 watts, and maybe self biasing? Budget is not a problem.

There are so many options, and a little conventional wisdom from the more knowledgeable would be helpful regarding which designs and implementations the forum have found that sound the best. The PSU can be solid state, and would probably prefer SS rectifiers. Although I'm open on this point.

Thank you for any ideas or suggestions.

-David
 
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Check out George's (tubelab) Simple SE design or the Tubelab SE here: http://www.tubelab.com/

These are good performing and sounding amplifier designs, come with lots of support both here and from George and have been built by lots of people. Provided you can solder, follow directions, and do simple troubleshooting you are virtually assured of a good working, reliable, nice sounding amplifier.
 
Are you more interested in stuffing a board, or going point-to-point? There are some good PTP kits out there (Bottlehead has 2, 3.5, and 8 watt class A amps).

If you're comfortable with all the machining and isolation procedures, I would think that a triode strapped 6V6 or EL84 is just too sweet and easy not to try!
-Paul
 
This hyper $$$$ 300B using tube regulation???
Wasn't it MJ that pretty much decreed tube regulation as way complex, expensive, fragile, and not really worth the effort as they don't perform anywhere near SS??
Note that He doesn't use any regulation for the filiments?
Perhaps one could use a transmitter tube thru a step down TX for filiments......that would be your "All Tube" set-up.
_________________________________________________Rick...........
 
Its a 1st project... simple is important. So for the power SE, and no DHTs, and probably just 2 stages.


Agreed, except for SE. An "El Cheapo" variant using current production "reissue" TungSol 6V6s and a DEEP Class "A" operating point meets all of the orginally enumerated requirements. As "folding green" is reasonably plentiful, buy superior O/P trafos from a proven winder, like: ElectraPrint, MQ, or Heyboer. Reducing the amount of loop NFB employed is possible, given top notch "iron".

50 KOhm PEC volume pots. plus 18 nF. PIO caps. working into 510 KOhm 12AT7 grid leak resistors will sound very good, while being reasonably "friendly" to upstream signal sources.
 
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This kit-amp series is being discontinued. Only three left at writing.
Called a Paramour they come with extremely good documentation and follow-up with a forum dedicated to the product line. Various avenues for upgrade as well. Good people there , many got their start with amps from this company and still regularly go to the forum years later to see what's happening.
 
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Hearinspace said:
a Paramour

If you needa well documented kit, it would certainly be one... we have a pair in house, i prefer both the RH84 derived EL84 monobloks & the El Cheapo derived Class A Push-pull (despite what Eli says it is at least 3 x as complicated as the RH84 -- don't get me wrong, El Cheapo is a very good amplifier when done with good iron and caps)

dave
 
doorman said:


Thank you everyone for the ideas and tips for a first tube amp! The Transcendent Sound OTL seems like a great product. I like the fact that I don't need to worry about bias and balancing the tubes over time.

To me a tube DIY amp needs to be point to point. Maybe it's just the nostalgic aspect of it?

Any other thoughts are appreciated.

I have access to a full machine shop, so building chassis's is no problem.

Thank you!

-David
 
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Joined 2005

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dw8083 said:



Thank you everyone for the ideas and tips for a first tube amp! The Transcendent Sound OTL seems like a great product. I like the fact that I don't need to worry about bias and balancing the tubes over time.

To me a tube DIY amp needs to be point to point. Maybe it's just the nostalgic aspect of it?

Any other thoughts are appreciated.

I have access to a full machine shop, so building chassis's is no problem.

Thank you!

-David


David,

I'm going to repeat the "El Cheapo" suggestion. That metal fabrication is a non-issue only makes things better.

You design the layout. Wiring is P2P, unless you engineer a PCB. The "finals" are self biasing. You set the CCSes in the LTP tails once and forget them, "forever". Nice, pre-matched, pairs of 6V6 O/P tubes will be available for a very long time, as electric guitar players use the type in LARGE numbers. :D Remember, O/P tubes require comparatively frequent replacement. Small signal types and especially rectifiers have lengthy service lives.
 
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Joined 2003
dw8083 said:
I have access to a full machine shop, so building chassis's is no problem.

And in an earlier post you owned up to having built transistor amplifiers - presumably they worked, otherwise you wouldn't have built them in the plural.

Strikes me that you're capable of building whatever you fancy in the 3-10W range. Perhaps the more important question is precisely what full-range loudspeakers you need to drive? And how loud? Heavy metal or Bach cantatas?
 
kuroguy said:
Machine shop? Build one from parts and skip the kit manufacturer's markup. There are a bunch of schematics available online and especially in these forums. I built a nice 832 amp for $350 in parts and machining the chassis/panels was half the fun.

Pics at http://buffalo.nas-central.org/index.php?title=User:Kuroguy

I'm sure others can suggest class A schematics.
Thanks for the post, kuroguy!
Great pics, etc.
Don
 
EC8010 said:


And in an earlier post you owned up to having built transistor amplifiers - presumably they worked, otherwise you wouldn't have built them in the plural.

Strikes me that you're capable of building whatever you fancy in the 3-10W range. Perhaps the more important question is precisely what full-range loudspeakers you need to drive? And how loud? Heavy metal or Bach cantatas?

Hi Bill, you are right. I not an amp designer by any means, but a capable builder with the essential tools (good scope, function generator, high accuracy DMM, high end weller iron). I've build a a few Passlabs DIY amps with great success.

I listen to 80% classic rock, 15% jazz, 5% classical. My choice in music probably screams "please use solid state and big box drivers".

Also starting to play with full range drivers; Pioneer BIB, Moth OB, and soon to order a pair of Lowther P6A at 15 ohms for an OB speaker project. The speakers are all high efficiency with nominal 8 ohm or up to 16 ohm loads.

Eli, I'll also take a harder look at El Cheapo.

Thank you!

-David
 
dw8083 said:


Hi Bill, you are right. I not an amp designer by any means, but a capable builder with the essential tools (good scope, function generator, high accuracy DMM, high end weller iron). I've build a a few Passlabs DIY amps with great success.

You've been holding out on us.

Pick a schematic, post the parts list that you plan to use and ask for comments. The people around here are always glad to help.
 
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