Post by novisnick on Aug 1, 2016 11:02:55 GMT -5
Review of the Tubes4HiFi ST70 Power Amp
By novisnick
The Tubes4HiFi ST70 is a modification of a Dynaco stereo tube power amplifier of the same name. The amplifier is rated at 35 watts per channel. Many of the Dynacos were made, and they were sold both under the Dynaco and Dynakit names. The availability and quality of the amplifier has made it a popular unit for home and commercial modifiers. The amp uses high quality transformers and four output tubes.
I enjoy music and sound, I am not an engineer, nor do I have any talent or ability to perform with any musical instrument but my voice but that was a very long time ago.
I purchased this amp used and it was rebuilt by audiobill. It contains mostly new parts. After my initial setup and listening session (in excess of 5 hours), I thought I had overdriven and blown a tweeter, I'm familiar with tube amps so it didn't even occur to me that it was the amp. Quick call to its maker and all is well. No big deal at all. Lesson one learned!
I’m enjoying this amp so much that I can't seem to turn it off! Here’s the related gear used for my listening sessions:
ST 70 amp
McIntosh C-220 preamp
REGA RP 6 with Exact II cartridge
Oppo 103 for Tidal streaming source
Mac Mini as an AAIF file source
Emotiva DC-1 as my DAC
Paradigm Studio 100's v5
Acoustically treated room
Zu interconnects
Zu Mission speaker cables
My music needs are simple; music needs to be enjoyable and fun with variety and depth. I love a wide range of music, as my selections will show. I enjoy everything from the jazz of The Dave Brubeck Quartet and Miles Davis to Led Zeppelin with some Bach organ music to electronica.
This wide a variety of music can be highly demanding of the associated gear.
Smoke filled rooms with jazz players doing their thing is as good as music gets. When I close my eyes and can nearly smell the smoke and cocktails in the room I know I have something special! The introduction of the McIntosh C220 preamp into my system a few months ago gave me almost all of that feeling.
Now with the addition of this little two-channel amp I believe I’m as close as I can get. We all know that the search for musical nirvana is never really over but it’s pretty close for jazz and other music that doesn't require gobs of power and high dBs.
Maybe there’s improvement to be had from a little tube rolling, but that could take a lifetime. Why? All of the possibilities in our age and time, and that doesn't even include all of the various suppliers of tubes let alone the different tubes that go into the amp and preamp. Each of which should change the sound somewhat. But I digress…
After some adjustments guided by audiobill, I’ve overcome almost all of the tweeters’ sibilance (known to be part of the Studio 100's signature). With this tamed, let’s talk about the treble in this system.
Cymbals are true but no longer over-emphasized; horns are nice but a shining star can be found in the guitars and pianos of well-recorded music.
I started to type this review after my first listening session where the tweeters sounded bright with this amp, but as I said, a quick call to audiobill fixed the problem. Now, the treble is softened just enough to make the musical tone of the system so much more enjoyable. This may not be as accurate, but it’s more pleasing to the ear, my ears at least.
Midrange is all you could want at these listening levels. I'm talking about 65 to 80 dBs, maybe a little more depending on the music and type. This amp will not blow out the neighborhood or get the law knocking on your door unless you’re in an apartment or townhouse. At higher volumes you realize this amp is not made for that but it’s still pretty good. Upright bass sounds accurate and pleasing.
As to bass, the amp doesn’t lack in that department at all. If the recording goes low, then this amp will take you there. I’m really surprised by the ability of this little two-channel with only 35wpc. The surprise is that I did not need any sub in my audition, at any time. Furthermore, almost of my listening was done without the use of the McIntosh C220’s tone controls. I never found the bass to be muddy or slow but rather smooth and compelling.
In conclusion, I would recommend this affordable amp to anyone looking for entry into the tube-amp market provided you don’t require head-banging volume. Absolute accuracy should not be the requirement of your enjoyment. I'm not even sure if “lacking accuracy” is what I'm trying to convey. The amp isn’t pinpoint exact, but what it lacks in accuracy, it makes up for in musical enjoyment.
To be fair, I’m comparing this 35wpc tube amp against my “normal” Emotiva XPR-1s with their 1,750 wpc @ 4 ohms. So, saying that this little amp sounds underpowered in comparison just isn't fair. The ST70 has made me extremely happy with most of my music. Some of the heavier lifting in rock-n-roll requires getting above the “dynamic knee.” In other words, for the speakers to dynamically jump, I need to crank up the volume. The ST70 can achieve good volume levels but if you’re a true head-banger, you will need a different (and more powerful) amp. This speaks highly for a 35-watt amp!
So yes, I'm very happy that I've made this purchase! Will I upgrade to tube mono-blocks in the future? Lets see what my funding (and my wife) has to say about that…
One more note - I was very hesitant to even try tubes due to my smallish listening room and the heat of living in “Emo South” country. But my Emotiva XPR-1 mono-blocks can put out more heat, and the ST70’s tubes cool very quickly after shutting down.
novisnick
By novisnick
The Tubes4HiFi ST70 is a modification of a Dynaco stereo tube power amplifier of the same name. The amplifier is rated at 35 watts per channel. Many of the Dynacos were made, and they were sold both under the Dynaco and Dynakit names. The availability and quality of the amplifier has made it a popular unit for home and commercial modifiers. The amp uses high quality transformers and four output tubes.
I enjoy music and sound, I am not an engineer, nor do I have any talent or ability to perform with any musical instrument but my voice but that was a very long time ago.
I purchased this amp used and it was rebuilt by audiobill. It contains mostly new parts. After my initial setup and listening session (in excess of 5 hours), I thought I had overdriven and blown a tweeter, I'm familiar with tube amps so it didn't even occur to me that it was the amp. Quick call to its maker and all is well. No big deal at all. Lesson one learned!
I’m enjoying this amp so much that I can't seem to turn it off! Here’s the related gear used for my listening sessions:
ST 70 amp
McIntosh C-220 preamp
REGA RP 6 with Exact II cartridge
Oppo 103 for Tidal streaming source
Mac Mini as an AAIF file source
Emotiva DC-1 as my DAC
Paradigm Studio 100's v5
Acoustically treated room
Zu interconnects
Zu Mission speaker cables
My music needs are simple; music needs to be enjoyable and fun with variety and depth. I love a wide range of music, as my selections will show. I enjoy everything from the jazz of The Dave Brubeck Quartet and Miles Davis to Led Zeppelin with some Bach organ music to electronica.
This wide a variety of music can be highly demanding of the associated gear.
Smoke filled rooms with jazz players doing their thing is as good as music gets. When I close my eyes and can nearly smell the smoke and cocktails in the room I know I have something special! The introduction of the McIntosh C220 preamp into my system a few months ago gave me almost all of that feeling.
Now with the addition of this little two-channel amp I believe I’m as close as I can get. We all know that the search for musical nirvana is never really over but it’s pretty close for jazz and other music that doesn't require gobs of power and high dBs.
Maybe there’s improvement to be had from a little tube rolling, but that could take a lifetime. Why? All of the possibilities in our age and time, and that doesn't even include all of the various suppliers of tubes let alone the different tubes that go into the amp and preamp. Each of which should change the sound somewhat. But I digress…
After some adjustments guided by audiobill, I’ve overcome almost all of the tweeters’ sibilance (known to be part of the Studio 100's signature). With this tamed, let’s talk about the treble in this system.
Cymbals are true but no longer over-emphasized; horns are nice but a shining star can be found in the guitars and pianos of well-recorded music.
I started to type this review after my first listening session where the tweeters sounded bright with this amp, but as I said, a quick call to audiobill fixed the problem. Now, the treble is softened just enough to make the musical tone of the system so much more enjoyable. This may not be as accurate, but it’s more pleasing to the ear, my ears at least.
Midrange is all you could want at these listening levels. I'm talking about 65 to 80 dBs, maybe a little more depending on the music and type. This amp will not blow out the neighborhood or get the law knocking on your door unless you’re in an apartment or townhouse. At higher volumes you realize this amp is not made for that but it’s still pretty good. Upright bass sounds accurate and pleasing.
As to bass, the amp doesn’t lack in that department at all. If the recording goes low, then this amp will take you there. I’m really surprised by the ability of this little two-channel with only 35wpc. The surprise is that I did not need any sub in my audition, at any time. Furthermore, almost of my listening was done without the use of the McIntosh C220’s tone controls. I never found the bass to be muddy or slow but rather smooth and compelling.
In conclusion, I would recommend this affordable amp to anyone looking for entry into the tube-amp market provided you don’t require head-banging volume. Absolute accuracy should not be the requirement of your enjoyment. I'm not even sure if “lacking accuracy” is what I'm trying to convey. The amp isn’t pinpoint exact, but what it lacks in accuracy, it makes up for in musical enjoyment.
To be fair, I’m comparing this 35wpc tube amp against my “normal” Emotiva XPR-1s with their 1,750 wpc @ 4 ohms. So, saying that this little amp sounds underpowered in comparison just isn't fair. The ST70 has made me extremely happy with most of my music. Some of the heavier lifting in rock-n-roll requires getting above the “dynamic knee.” In other words, for the speakers to dynamically jump, I need to crank up the volume. The ST70 can achieve good volume levels but if you’re a true head-banger, you will need a different (and more powerful) amp. This speaks highly for a 35-watt amp!
So yes, I'm very happy that I've made this purchase! Will I upgrade to tube mono-blocks in the future? Lets see what my funding (and my wife) has to say about that…
One more note - I was very hesitant to even try tubes due to my smallish listening room and the heat of living in “Emo South” country. But my Emotiva XPR-1 mono-blocks can put out more heat, and the ST70’s tubes cool very quickly after shutting down.
novisnick
