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Bossman

What is a good starter Tube Amp?

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let me digest this a bit... thanks you two, I appreciate it.

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On ‎11‎/‎8‎/‎2016 at 9:49 AM, Bossman said:

I just wanted to say thanks to all the members who gave me advice on this topic! So after a couple of months I finally decided to pull the trigger on a tube amp. I went with Jim's suggestion in particular and chose a variant of a Aiqin Audio (Douk Audio) EL34 single ended triode SET amp. It uses a 5Z3P Rectifier tube, 2 6N9P Preamp tubes and 2 EL34 Power tubes and is good for 12 wpc in default mode and 8 wpc in triode mode?. I have the amp currently hooked up to a pair of Cornscalas and wow this thing sounds NICE! Being my first tube amp, I am truly impressed with the sound quality. I can now fully understand the synergy between Klipsch speakers and SET amps. Huge soundstage, great depth, width and height with an abundance of realism. 

Here is the amp I purchased http://www.ebay.com/itm/Nobsound-EL34-Single-ended-Class-A-Stereo-Tube-Amplifier-Rectifier-HIFI-AMP/281312152025?_trksid=p2047675.c100005.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D2%26asc%3D39825%26meid%3D3826de3136f74c9d8ffec2f22b77455a%26pid%3D100005%26rk%3D3%26rkt%3D6%26sd%3D271612287363

 

 

 Contradictions!  One clarification. That is not a SET amplifier. SET stands for Single, Ended, Triode. The EL34 is a Pentode type tube. Don't fret about it people make the mistake with the amplifier type all the time.  

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12 hours ago, wdecho said:

Nothing sounds like a SE300B and I only have the Gold Lion 300B tubes not some of the very expensive ones.

 

Nothing sounds like a 2A3...or a 45...directly heated of course...

Don't get me wrong, I love the lush sound of 300B, but one is stuck with the choice of newer offerings of 300B. Unless a guy can afford the old NOS 300B, or the new WE editions of 300B...I sure can't...(I have only heard newer offerings of 300B)

 

Older 2A3 or 45 tubes can be found for okay prices, and one doesn't have to necessarily buy NOS.

Over the course of 2 years I scrounged about for Sylvania 5930/2A3W. They are homely oversized looking GT types, compared to globes and ST types.

But, they are 50's era military regulator tubes, boxed H plate style with smoked glass. They may ugly, but I'm confident they won't wear out in a couple years...provided they are operated within the tube's parameters, the 5930s should outlive us all.

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12 hours ago, NOSValves said:

 

 

 Contradictions!  One clarification. That is not a SET amplifier. SET stands for Single, Ended, Triode. The EL34 is a Pentode type tube. Don't fret about it people make the mistake with the amplifier type all the time.  

 

 

Ok I looked, what output tubes are SET? I see lots of amp builders using the EL34 and calling the amp SET.  

 

Mark

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I think the EL 84, and the tubes Mike S was talking about are some common set tubes.  With so many tube selections and lot push- pulls amps are popular due to a bit more power.  I've never heard a set amp so, I can't speak to their SQ but, I have been very pleased with my Ultarlinear push- pull amp.  Tube cost and choices are an important consideration in buying a tube amp for me.

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EL84/6BQ5 is a pentode.

 

You can take a pentode (not all necessarily) and tie the screen grid to the plate through a lowish value resistor, and "triode strap" the tube.

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What do you guys think about this then: Inspire

From your amp descriptions/characterizations above, I might be a more se45 guy than a 300b guy... 

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If I could jump in here and as a question?

 

I listen mainly to Pink Floyd Robin Trower etc, then an occasional dose of Black Sabbath Iron Maiden. I have Cornwalls in a 15x15 room and believe I need a SET type amp, will the choice of tubes I use in it dictate the sound I get? What else in the equation dictates the sound you are looking for?

It doesn't have to be extremely loud (I have another amp for that) but I would like to be able to listen to it at a high level.

 

Thanks!

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1 hour ago, DaMuffinMan said:

If I could jump in here and as a question?

 

I listen mainly to Pink Floyd Robin Trower etc, then an occasional dose of Black Sabbath Iron Maiden. I have Cornwalls in a 15x15 room and believe I need a SET type amp, will the choice of tubes I use in it dictate the sound I get? What else in the equation dictates the sound you are looking for?

It doesn't have to be extremely loud (I have another amp for that) but I would like to be able to listen to it at a high level.

 

Thanks!

The answer to your first question is long, but there are many posts (including wdecho's just above) that describe the differences (and apparent similarities in short, casual comparisons) between types.  Read up, or better yet, get ears on.  An audible picture says a thousand words.

As for loudness, I wouldn't worry too much.  You have a more powerful, presumably linear amp as a backup, which is good.  It's nice to have a reference, and it's nice to go loud on occasion.  But in a small room like yours, you won't need much to get pretty loud.  Also consider that the lower the power of the amp you go with, the more likely it's acting as an ear-friendly compressor, and will thus sound a bit louder than you would expect.    

 

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2 hours ago, DaMuffinMan said:

will the choice of tubes I use in it dictate the sound I get? What else in the equation dictates the sound you are looking for?

It doesn't have to be extremely loud (I have another amp for that) but I would like to be able to listen to it at a high level.

 

 

Yes, the tubes can dictate the resultant sound based on the chosen operating parameters.  Any tube can be operated over a range of voltages and current which can affect its output power and distortion.  Different tubes can be made to sound very similar by juggling those parameters as well.  Then there's the issue of the characteristics of the output transformer.  In the case of SETs, some folks like to have a little more 2nd harmonic distortion as it "warms" up the sound a bit.  Also, there's the issue of the amplifier's output impedance and the effect of varying speaker impedance over the audio band.  In general, most Klipsch speakers sound wonderful with many different types of tube amps.  As to listening level, I don't recall which speakers you are using and the distance from the speakers to your listening position.  With that information, an approximation of the required output power can be made if you know the actual listening level (everyone's definition of a high level is different).

 

Maynard 

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Thanks guys.

" I don't recall which speakers you are using and the distance from the speakers to your listening position".

 

The speakers are Cornwall 1.5 1983 versions.

The listening distance is aoorox 10 feet.

 

" characteristics of the output transformer. "  What are the different types of output transformers used in SET amps?

 

" actual listening level "  for this amp I want to be able to hear the music, I can use my other amp to feel it. On a level of 1-10 where 10 is ear meltin and 1 is a quiet whisper, I would like to see a 6-7 with this amp.

 

 

 

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Let's say that the real world sensitivity of your speakers is 100 db/w/m.  One wpc would give you a level of around 93 db at your 10 foot listening position.  That's very loud to me, yet one of the local guys would consider that a whisper (he normally listens at 105+ db).  So, as you can see, this is a very subjective determination.  Four wpc would bring your level to about 99 db.  One point to consider is that SETs and loud levels are usually found to be mutually exclusive.  The hallmark of SETs is the imaging and soundstage size.  Unfortunately, the louder you listen the more the room itself contributes to the sound and often results in smearing of the musical details which can otherwise be enjoyed at much lower levels.  It's all about choices and options.  You won't know what the best alternative is until you try it in your system.  And keep in mind that higher power in the SET world (say above 2 or 3 wpc) can get more expensive than a pentode amp of higher power.

 

The types of output xfmrs used in any kind of tube amp are as varied as the amps themselves.  They are available at all different price points, and can have very different characteristics.  One point of confusion is that some manufacturers rate the frequency response of their products at their full rated output power (such as Hammond), while others rate the response at only 1 watt output regardless of what the transformer can handle.  In the latter case, the bandwidth of the xfmr will be reduced at full power output.  So, on the surface, a Hammond xfmr spec may look much worse than a competing product but in reality is vastly superior. 

 

That's my abbreviated response to your questions.  This stuff can be debated in many different ways until the cows come home.  I hope that William, Mike, Ski Bum, and others add their perspectives to the discussion.

 

Maynard  

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Find a old Magnavox console amplifier...a single-ended 6BQ5 pentode job like a 8600 series. They can still be had for good prices if one pays attention.

In stock condition some 8600 type/series have a tone control type EQ in the circuit, lotsa extra caps and parts. Most parts can be chucked, cutting the parts count of the amp circuit to around 20-25. Just a 3-4 watt per side power amplifier, with a 6EU7 driver...the output trannies ring like hell without any feedback compensation, so Triode strapping is probably no option with the stock OPTs. With proper feedback compensation, (using a C and R) the little amplifiers can sound rather balanced for what they are.

 

You won't get bone shaking bass in the lower registers, but you'll hear it. These little console amps are stupid simple, and can be a good starter amp for poor slob who can't afford to just buy a tube amplifier. They sound a lot bigger than they look...

 

The RH84 is another simple single-ended 6BQ5 pentode connected circuit, with a type of Schade feedback compensation. I think a guy could build one for under 400 bucks...maybe even less...I listen to the pretty much the same music as you, DaMuffinMan...

My listening area is smaller, around 12' by 14'. I use Cornwalls with the listening position at around 8 feet. The little 6BQ5 single-ended amplifier gets plenty loud enough for me.

When a guy is interested in the sound of single-ended tube amplifiers, it is good to keep a open-mind about the sound quality differences about a SE tube amp, and have less concern about how loud it gets. Try a SE amp, or better listen to one. If the SE tube sound leaves one waning, then you know you may want to go with the higher power of a push-pull amplifier.

 

There is something to said for a good well-designed 6BQ5/EL84 push-pull amplifier.

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1 minute ago, wdecho said:

OPT's are nothing more than wire wrapped around a core. No magic fairy dust sprinkled on during manufacturing. Difference in sound between brands, sure just like Pepsi and Coca Cola.

 

Ouch.

With all due respect, you may want to learn how to bench test various output transformers before coming up with that response.

I get what you are saying, and yes Edcor makes a quality product, but don't put your faith in published specs...even Magnequest for that matter.

 

Have you sold the One-Electrons in favor of the Edcors due to the vague differences...or was the difference subtle enough to keep using them?

Hell, I'll buy them from ya if that's the case...

 

There is differences...and yes, there is a dividing line between paying for a quality product or buying something to prove your stupid rich, but there is differences, trust me.

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I realize this strays from thread topic but now that UL/triode, SET and push pull have come up for comment I thought I'd offer opinion. Speakers are KHorns, RB75's and KP450's Pro line with B&C driver atop EAW horn (Frankensteins).

i have long favored low power SET, EL84 and EL34 strapped to run single ended. Until recently my favorites are my George Wrights 2a3 DHT SET monoblocks. I really thought they might be my last stop Until I bought another pair of Quicksilver Horn Mono's, EL34 push pull. I have to say these are the most natural, neutral sounding amps I have heard in a long time. From top to bottom everything just sounds - right. Nothing emphasized, nothing omitted the kind of sound where there is nothing negative to point to. Pure neutral. I've had may amps where one particular sonic feature stands out and another is missing. These Horn Mono's are doin' it for me. No triode to UL switch, no SET emphasis on particular passages just good'ol push pull. Don't quote me but I believe Quicksilver use Magnequest trannies? I could be wrong --?

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On 11/10/2016 at 5:15 AM, tube fanatic said:

Thanks for asking, but I'm only doing custom builds locally where I have access to the systems in which the amps will be used.  With your LSIIs, power certainly is of no concern (I recently sent a low power SET to a forum member to use with his LSs, and he said the power output is enough to create extremely loud listening levels), so I would consider either of these:

 

http://www.decware.com/newsite/SE34I.htm

 

http://www.decware.com/newsite/SE84CKCS.html

 

Both can be directly driven by your source, so a preamp is unnecessary.  And, in my opinion, the less electronics in the signal path, the better.  More electronics can only crap up the sound.

 

Between the lifetime warranty to the original owner, and the 30 day return option, you can't lose (and they are point to point wired/made in the US).  I have never read anything negative about Decware amps, and it's rare to see them come up on the used market (I ought to ask Deckert for a commission given how often I recommend his stuff!). 

 

Maynard

 

 

 

these monos look very tasty... we're into VRD neighborhood now in terms of pricing.

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20 hours ago, tube fanatic said:

 

 

The types of output xfmrs used in any kind of tube amp are as varied as the amps themselves.  They are available at all different price points, and can have very different characteristics.  One point of confusion is that some manufacturers rate the frequency response of their products at their full rated output power (such as Hammond), while others rate the response at only 1 watt output regardless of what the transformer can handle.  In the latter case, the bandwidth of the xfmr will be reduced at full power output.  So, on the surface, a Hammond xfmr spec may look much worse than a competing product but in reality is vastly superior. 

 

 

 

Maynard  

Hammond is considered a good trans?

I was talking to one builder and they said they use Hammond, and not knowing any better I couldn't judge whether or not that would be better than some other build that might specify there own custom trans.

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Getting back to the original question which was what's a good starter tube amp, I am in the search for an older US made tube amp like the Scott 222/299 or Fisher 10x series. I prefer an integrated amp (vs. seperate power and pre-amp). the reason for the US choice is I recall the amazing US made tube equipment when I was a kid and now I prefer my hard earned $ stay in the US when possible.

 

I see what's on eBay but if someone on this forum  has one for sale-  could you please contact me or point me to a place on this Forum where I can find such equipment for sale ?

 

Thank you

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 My apologies, I found the  'Garage Sale' section .:huh:

Here's a pic of the  Scott amp I'm considering. The bridge rectifier has been replaced but from the attached picture of the underside I can't tell if those white ceracaps are the originals and what further refurbishment is needed for reliability?

I'm hoping someone here can make more sense of the picture.

I'm new to the Forum  and if there's a more appropriate place  for such Qs please chime in.  

Scott  underchassis.png

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This is the person you want to speak directly with...

 

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