Any experience with Chinese SET amps?

[gld3gld3]

I have someone locally that is selling his mostly unused EL-34 stereo tube amp like the ones linked here (link and link). I've been wanting to dip my toes into tube amplification and at this price it's hard to refuse. He's selling it for $250 with the original Chinese tubes plus the following tubes: matched pair of Sylvania JAN CHS 6SL7WGT 6SL7 6SL7W (w/BROWN BASE); matched pair of RCA 6SL7GT; one Sylvania 5U4G rectifier; and a new matched pair of JJ E34L.

This amp would be driving my Tekton M-Lores, which have a claimed sensitivity of 95dB 1W@1m. I know this amp wouldn't be the TOTL tube amp, but would it be worth trying at this price? Would it be a descent introduction to the sound of tube amplifiers or not? 

If anyone has any experience with this amp or similar ones I would appreciate some feedback! Thanks.

[KeithL]

If you're new to tubes then you should note that this is a SET amp (single-ended triode)......

Because SET amps use a single output tube in each channel, they have much  higher distortion, and a much "toobier" sound, than even other tube amplifiers.
They usually have what's called "a monotonic distortion product" - which means that distortion starts at a low level and increases gradually as you turn them up.
(With solid state amps, and even push-pull tube designs, the distortion remains relatively low at low volume settings, but increases suddenly near full power.)

Nov 1, 2017 10:33:28 GMT -5 gld3gld3 said:

I have someone locally that is selling his mostly unused EL-34 stereo tube amp like the ones linked here (link and link). I've been wanting to dip my toes into tube amplification and at this price it's hard to refuse. He's selling it for $250 with the original Chinese tubes plus the following tubes: matched pair of Sylvania JAN CHS 6SL7WGT 6SL7 6SL7W (w/BROWN BASE); matched pair of RCA 6SL7GT; one Sylvania 5U4G rectifier; and a new matched pair of JJ E34L.

This amp would be driving my Tekton M-Lores, which have a claimed sensitivity of 95dB 1W@1m. I know this amp wouldn't be the TOTL tube amp, but would it be worth trying at this price? Would it be a descent introduction to the sound of tube amplifiers or not? 

If anyone has any experience with this amp or similar ones I would appreciate some feedback! Thanks.

[Loop 7]

Maybe audiobill can weigh in here.

[gld3gld3]

Nov 1, 2017 10:45:53 GMT -5 KeithL said:

If you're new to tubes then you should note that this is a SET amp (single-ended triode)......

Because SET amps use a single output tube in each channel, they have much  higher distortion, and a much "toobier" sound, than even other tube amplifiers.
They usually have what's called "a monotonic distortion product" - which means that distortion starts at a low level and increases gradually as you turn them up.
(With solid state amps, and even push-pull tube designs, the distortion remains relatively low at low volume settings, but increases suddenly near full power.)

Nov 1, 2017 10:33:28 GMT -5 gld3gld3 said:

I have someone locally that is selling his mostly unused EL-34 stereo tube amp like the ones linked here (link and link). I've been wanting to dip my toes into tube amplification and at this price it's hard to refuse. He's selling it for $250 with the original Chinese tubes plus the following tubes: matched pair of Sylvania JAN CHS 6SL7WGT 6SL7 6SL7W (w/BROWN BASE); matched pair of RCA 6SL7GT; one Sylvania 5U4G rectifier; and a new matched pair of JJ E34L.

This amp would be driving my Tekton M-Lores, which have a claimed sensitivity of 95dB 1W@1m. I know this amp wouldn't be the TOTL tube amp, but would it be worth trying at this price? Would it be a descent introduction to the sound of tube amplifiers or not? 

If anyone has any experience with this amp or similar ones I would appreciate some feedback! Thanks.

Thanks Keith. I have read enough about SET amps to absorb this information. I have a good solid state class AB amp in the mini-x. What I am looking for is a different sound to see if I like it, even if only with some genres, albums, etc. I'm keeping my solid state amp, but I am looking for something else to add variety or perhaps add unique strengths to my system. For example, I could probably live with a tube amp that may be inferior in some aspects of sound reproduction, but is superior (even subjectively) in some other aspect of sound. For example, one thing I would be interested in is a greater sense of width/depth to the soundstage. If this SET tube amp could improve on soundstage alone I might be interested in adding it to the system, especially if the other aspects of the sound aren't horrible. My current system with the mini-x has a fairly flat soundstage. It sounds fine, but I don't think it's the last word in this regard. I understand that speakers and setup might impact this quite a bit, but I'm fairly stuck with the position/room environment that I have. So, if a tube amp could help here I would go for it.

What aspects of sound do people find that tube or SET amps excell in? I would be very interested in people's experience with switching between SS and tube amps.

[DYohn]

In my experience, SET amps can sound very nice but only at low power levels with high efficiency speakers. They tend to sound like ass when you turn them up too high, mostly for the distortion level reasons Keith describes. I use a SET amp with 96db efficient speakers in my main 2-channel system, and it is great sounding... unless I try to turn it up too far. But keep it at around less than one watt average output and it's sublime, especially in the midrange. Vocals are perfe4ct.

That being said I have no experience with the cheap Chinese tube amplifiers that are all over the webz.

[gld3gld3]

Nov 1, 2017 13:05:31 GMT -5 DYohn said:

In my experience, SET amps can sound very nice but only at low power levels with high efficiency speakers. They tend to sound like ass when you turn them up too high, mostly for the distortion level reasons Keith describes. I use a SET amp with 96db efficient speakers in my main 2-channel system, and it is great sounding... unless I try to turn it up too far. But keep it at around less than one watt average output and it's sublime, especially in the midrange. Vocals are perfe4ct.

That being said I have no experience with the cheap Chinese tube amplifiers that are all over the webz.

Thanks for sharing your experience DYohn. I don't listen to music very loud as I am typically listening at night with my kids in bed. Loud for me would be peaks at 80-85 dB at my listening position (with no one else at home). I am not totally certain, but from my calculations I think I would be able to get close to these levels while staying at or below that 1 watt critical value.

[leonski]

With the right speakers? Worth a try.

I see sensitivity ratings for the Lore, but no data on phase. Also? One review was of the '8th wonder of the world' level, so I'm writing that one off.

Other than that? Maybe try to find an old Stereo70 for test?

[KeithL]

It really depends on what you're looking for.

Something like a Stereo 70 is going to sound relatively "normal", with a little bit of "tube sound" in the midrange mostly - and would be an excellent starting point.
(You might describe it as "fullness" or "a sort of liquid smoothness".... )
However, I listened to a Yaqin SET amp once that I describe to people as "sounding like you were listening to music while your head was submerged in a bucket of Karo syrup".
Unfortunately, the designers of at least some of the Chinese amps seem to have done their best to exaggerate the "tube sound" far beyond what it would normally be.

[leonski]

An Acquantance bought the MinWatt and was so dissatisfied, especially after good reviews, that he sent it back. And had a hassle doing to.

Stereo 70 has 'stood the test of time' and has many modifications / rebuilds / options available. I particularly like getting rid of the rectifier tube and going SS in that circuit.

OP has nothing to go on and needs a couple 'data points' to begin finding out if what HE values in music reproduction can be found in Tube Gear.

[brubacca]

$250 including extra tubes seems like a minimal investment to try a SET amp. There is a whole audio subculture that swears by them. As long as the one your friend is selling is in good working order.

[mgbpuff]

This won't be an investment. You are buying an inexpensive piece of old technology, probably copied from some old documents on a long since expired patented amplifier design, if there ever was one. Try it, but if it were me I would be looking for something used and something American (which would probably be more resalable).

[garbulky]

Nov 1, 2017 13:19:03 GMT -5 gld3gld3 said:

Nov 1, 2017 13:05:31 GMT -5 DYohn said:

In my experience, SET amps can sound very nice but only at low power levels with high efficiency speakers. They tend to sound like ass when you turn them up too high, mostly for the distortion level reasons Keith describes. I use a SET amp with 96db efficient speakers in my main 2-channel system, and it is great sounding... unless I try to turn it up too far. But keep it at around less than one watt average output and it's sublime, especially in the midrange. Vocals are perfe4ct.

That being said I have no experience with the cheap Chinese tube amplifiers that are all over the webz.

Thanks for sharing your experience DYohn. I don't listen to music very loud as I am typically listening at night with my kids in bed. Loud for me would be peaks at 80-85 dB at my listening position (with no one else at home). I am not totally certain, but from my calculations I think I would be able to get close to these levels while staying at or below that 1 watt critical value.

If it helps B'zilla ran a set of modified Heathkit monoblock amplifiers which maybe did 5 watts per channel in to a set of Tekton Pendragons. The sound was fabulous! Though it was colored, it gave the XPA-1 gen 2 a really hard run for the money. Probably the closest any amp has been to it imo. It really made me re think what good sound meant because it was definitely outstanding.

Since then I haven't heard other tube amps do what it did. Not even the very well regarded Bob Latino line of amps. The best I can say was that everything was vivid, very naturally portrayed and all around you. You could follow the different lines of all these instruments in 3d space through a "vivid" filter.

Unfortunately, these aren't available as they were custom made by B'zilla repurposed from two stereo heathkits to become a set of monoblocks.
Here's my link to the visit.
emotivalounge.proboards.com/post/840667/thread

[gld3gld3]

Nov 1, 2017 14:43:17 GMT -5 KeithL said:

It really depends on what you're looking for.

Something like a Stereo 70 is going to sound relatively "normal", with a little bit of "tube sound" in the midrange mostly - and would be an excellent starting point.
(You might describe it as "fullness" or "a sort of liquid smoothness".... )
However, I listened to a Yaqin SET amp once that I describe to people as "sounding like you were listening to music while your head was submerged in a bucket of Karo syrup".
Unfortunately, the designers of at least some of the Chinese amps seem to have done their best to exaggerate the "tube sound" far beyond what it would normally be.

Noted. I don't want my amp to sound like my head is submerged in any highly viscous substance! I will definitely have to listen to this thing if I decide to go forward with it. The owner has said that he will demo it at his house. The only thing is that it's a two our drive from here. Now, I am regularly on the road for work in his area, so it may work out that I can stop by and give it a listen without much extra effort.

[gld3gld3]

Nov 1, 2017 15:03:28 GMT -5 brubacca said:

$250 including extra tubes seems like a minimal investment to try a SET amp. There is a whole audio subculture that swears by them. As long as the one your friend is selling is in good working order.

I agree. The price makes this very tempting and a minimal investment. Nonetheless, money is still money and I don't want to throw it away. I think I will have to give it a listen, at least in the sellers rig before deciding...

[gld3gld3]

Nov 1, 2017 15:20:11 GMT -5 mgbpuff said:

This won't be an investment. You are buying an inexpensive piece of old technology, probably copied from some old documents on a long since expired patented amplifier design, if there ever was one. Try it, but if it were me I would be looking for something used and something American (which would probably be more resalable).

I definitely prefer to buy American when I can. However, similar new amps stateside are outside of my price range. Used ones might occasionally be had at lower prices, but probably still not in the price range of this unit. The Dynacos that have been mentioned in this thread still run higher than the Chifi unit from some casual glances on eBay (and often in questionable condition). Either way I am probably looking at buying something second-hand. I just want to dip my toes and maybe see what some of the fuss is about. Or should I go for the long game and save for a more reliable, American-made product? These are things I must ponder...

[garbulky]

Nov 1, 2017 15:32:57 GMT -5 garbulky said:

Nov 1, 2017 13:19:03 GMT -5 gld3gld3 said:

Thanks for sharing your experience DYohn. I don't listen to music very loud as I am typically listening at night with my kids in bed. Loud for me would be peaks at 80-85 dB at my listening position (with no one else at home). I am not totally certain, but from my calculations I think I would be able to get close to these levels while staying at or below that 1 watt critical value.

If it helps B'zilla ran a set of modified Heathkit monoblock amplifiers which maybe did 5 watts per channel in to a set of Tekton Pendragons. The sound was fabulous! Though it was colored, it gave the XPA-1 gen 2 a really hard run for the money. Probably the closest any amp has been to it imo. It really made me re think what good sound meant because it was definitely outstanding.

Since then I haven't heard other tube amps do what it did. Not even the very well regarded Bob Latino line of amps. The best I can say was that everything was vivid, very naturally portrayed and all around you. You could follow the different lines of all these instruments in 3d space through a "vivid" filter.

Unfortunately, these aren't available as they were custom made by B'zilla repurposed from two stereo heathkits to become a set of monoblocks.
Here's my link to the visit.
emotivalounge.proboards.com/post/840667/thread

Here are the amps I'm referring to. Look at that! Utterly sublime.

[gld3gld3]

Nov 1, 2017 15:32:57 GMT -5 garbulky said:

Nov 1, 2017 13:19:03 GMT -5 gld3gld3 said:

Thanks for sharing your experience DYohn. I don't listen to music very loud as I am typically listening at night with my kids in bed. Loud for me would be peaks at 80-85 dB at my listening position (with no one else at home). I am not totally certain, but from my calculations I think I would be able to get close to these levels while staying at or below that 1 watt critical value.

If it helps B'zilla ran a set of modified Heathkit monoblock amplifiers which maybe did 5 watts per channel in to a set of Tekton Pendragons. The sound was fabulous! Though it was colored, it gave the XPA-1 gen 2 a really hard run for the money. Probably the closest any amp has been to it imo. It really made me re think what good sound meant because it was definitely outstanding.

Since then I haven't heard other tube amps do what it did. Not even the very well regarded Bob Latino line of amps. The best I can say was that everything was vivid, very naturally portrayed and all around you. You could follow the different lines of all these instruments in 3d space through a "vivid" filter.

Unfortunately, these aren't available as they were custom made by B'zilla repurposed from two stereo heathkits to become a set of monoblocks.
Here's my link to the visit.
emotivalounge.proboards.com/post/840667/thread

Very cool. Those would be sweet. Almost as good as the XPA-1 gen 2? High praise! The sound you describe is intriguing to say the least. I really dig the sound of accoustic instruments, especially stringed instruments, and the effect of these heathkits is something I would probably really enjoy. Hmm...thanks for sharing.

[DYohn]

Nov 1, 2017 15:38:29 GMT -5 gld3gld3 said:

Nov 1, 2017 15:03:28 GMT -5 brubacca said:

$250 including extra tubes seems like a minimal investment to try a SET amp. There is a whole audio subculture that swears by them. As long as the one your friend is selling is in good working order.

I agree. The price makes this very tempting and a minimal investment. Nonetheless, money is still money and I don't want to throw it away. I think I will have to give it a listen, at least in the sellers rig before deciding...

Buyer beware, and you often do get what you pay for when you go cheap. Just as a point of reference, the F2A tubes in my amp cost more than that...

[KeithL]

As long as you get to listen to it first, you don't have anything to lose, and you don't have to worry about whether it works or not.
You can start out with relatively little investment..... and get most of it back if you decide tubes don't float your boat...... or if you decide to buy something more expensive later.

As for the comment about "old technology".......
Tubes are old technology, and the core technology really hasn't changed in thirty or forty years, so don't feel bad about "old designs".
While some of the newer designs offer whiz-bang features like auto bias, the basic technology hasn't changed, and they've also added more things to go wrong.
(There really hasn't been a significant new technology patent in tubes since "Williamson Ultralinear".)

www.pearl-hifi.com/06_Lit_Archive/02_PEARL_Arch/Vol_01/Sec_02/105_UL-ing_the_Williamson.pdf

It's also smart to stay away from used units in questionable condition....
A lot of vintage units are at the age where stuff is starting to go wrong (and, no, most vintage units were not built with awesome parts that last forever).
You really don't want to think about rebuilding, and replacing filter caps, and such things..... at least until you decide tubes are for you

Nov 1, 2017 15:48:29 GMT -5 gld3gld3 said:

Nov 1, 2017 15:20:11 GMT -5 mgbpuff said:

This won't be an investment. You are buying an inexpensive piece of old technology, probably copied from some old documents on a long since expired patented amplifier design, if there ever was one. Try it, but if it were me I would be looking for something used and something American (which would probably be more resalable).

I definitely prefer to buy American when I can. However, similar new amps stateside are outside of my price range. Used ones might occasionally be had at lower prices, but probably still not in the price range of this unit. The Dynacos that have been mentioned in this thread still run higher than the Chifi unit from some casual glances on eBay (and often in questionable condition). Either way I am probably looking at buying something second-hand. I just want to dip my toes and maybe see what some of the fuss is about. Or should I go for the long game and save for a more reliable, American-made product? These are things I must ponder...

[pknaz]

Maybe purchase from an online vendor that allows you to return the items without question if you don't like them on your system in your room?