+9
Maintarget
peterh
sKiZo
corndog71
deepee99
Rabindu
arledgsc
Kentley
audiobill
13 posters
ST-120 Review
audiobill- Posts : 425
Join date : 2014-03-13
Location : Albany, NY
Kentley- Posts : 496
Join date : 2015-03-06
Age : 72
Location : Worcester, MA
Now THAT'S a review. Not only is it well-written and accurate, it is detailed beyond any other I've read (or written myself, for that matter). And it is balanced by a few criticisms, which are justifiable. Bravo, Boomzilla!
arledgsc- Posts : 503
Join date : 2012-11-30
Nice review Boom. I agree with conclusions. The positives far outweigh the few negatives and I feel the same way.
Rabindu- Posts : 6
Join date : 2016-02-13
Age : 69
Location : Mississauga, Ontario, Canada
As an owner of this amp and having built it myself, reading this review gave me that warm and fuzzy feeling all over. I can only say that it always gives me great listening pleasure driving my JBL L36's along with a Velodyne sub. The SP-14 pre and PH-16 phono stage are the icing on the cake. In the future I would love to build a pair of M125's just because building gives me great satisfaction. As for the article, well done!
Mike Kampman
Mike Kampman
deepee99- Posts : 2244
Join date : 2012-05-23
Location : Wallace, Idaho
Getting a nice bit of chatter on Bob's Facebook page.
corndog71- Posts : 840
Join date : 2013-03-19
Location : It can get windy here
The best part is that for the creatively inclined one can fashion an amp to suit their needs. I too find the old dynaco chassis limiting, crowded, and ultimately unattractive.
I made mine the way I wanted with the parts I wanted and it's been a real champ of an amp! I still want to build a custom ST70 but right now I'm building custom EL84 monoblocks.
I made mine the way I wanted with the parts I wanted and it's been a real champ of an amp! I still want to build a custom ST70 but right now I'm building custom EL84 monoblocks.
sKiZo- Posts : 1530
Join date : 2013-04-01
Location : Michigan USA
Can't imagine why anyone would want to change anything ... leave well enough alone! ;-}
peterh
peterh- Posts : 1869
Join date : 2012-12-25
Location : gothenburg, sweden
audiobill wrote:By our own Boomzilla!!
http://hometheaterhifi.com/reviews/amplifier/power-amplifier/vacuum-tube-audio-st-120-tube-power-amplifier-review/
Two of the negative issues is easily fixed, like i have done.
-An IEC well can be positioned at the back, a shop with a mill can do that as
a temporary solution. Suitable IEC intakes ( with built-in fuse) will be part of
the kit.
- A SSR ( Solid-state relay) and a power-control connector can be included,
AT worst it need one or two screwmounts. The signal connector can use
the unused fuse ( that is replaced by the IEC ). This will augument the
powerswitch at the back with a remote control possibility.
In the future this could be combined with the delay-board and some extra
functionality ( such as a turn on delay that protects from power glitches)
deepee99- Posts : 2244
Join date : 2012-05-23
Location : Wallace, Idaho
Yeah, right, Dr. Monarch!sKiZo wrote:Can't imagine why anyone would want to change anything ... leave well enough alone! ;-}
Maintarget- Posts : 227
Join date : 2013-02-10
deepee99 wrote:Yeah, right, Dr. Monarch!sKiZo wrote:Can't imagine why anyone would want to change anything ... leave well enough alone! ;-}
I was thinking the same thing deepee99
I'm surprised the post didn't include a photo of the famous "Monarch Amp" of course I'm just jealous
Dogstar- Posts : 361
Join date : 2014-06-23
Nothing much to this – plug in the tubes (they’re keyed only go in one way, so you can’t mess it up), set the output tube bias (a multimeter & small screwdriver will be required), hook up the speakers & inputs, turn it on – and instant music!
We know this paragraph is not instructions for setup but just to be sure speakers need to be hooked up before the amp is powered up to set the bias.
We know this paragraph is not instructions for setup but just to be sure speakers need to be hooked up before the amp is powered up to set the bias.
Rabindu- Posts : 6
Join date : 2016-02-13
Age : 69
Location : Mississauga, Ontario, Canada
The only thing I found to be a nuisance is the power switch being on the back. I originally ordered my kit with the attenuator that's mounted in place of the stereo/mono switch which as time went by found that I could do without since building an SP-14. Therefore I removed it and moved the power switch in its place, no more reaching over hot tubes to turn the amp off. The only other thing that I can think of that would be an improvement is to have the RCA input jacks on the rear panel, otherwise the layout is just fine as is.
Mike Kampman
Mike Kampman
monkuboy- Posts : 46
Join date : 2016-03-23
Rabindu wrote:The only thing I found to be a nuisance is the power switch being on the back. I originally ordered my kit with the attenuator that's mounted in place of the stereo/mono switch which as time went by found that I could do without since building an SP-14. Therefore I removed it and moved the power switch in its place, no more reaching over hot tubes to turn the amp off. The only other thing that I can think of that would be an improvement is to have the RCA input jacks on the rear panel, otherwise the layout is just fine as is.
Mike Kampman
When I reach over to turn off the amp after using it a while, if I'm wearing short sleeves I always think about making sure they don't catch on fire.
pichacker- Posts : 103
Join date : 2016-08-01
Age : 60
Location : Near to London - UK
I moved my RCA's to the rear (see my posts) and the only observation I can make having fitted mine centre rear is that the mains transformer has a large magnetic field and this can easily induce hum onto the input leads.
In hindsight best for it to be to one side and move the speaker terminal? Not going to do it as cutting the stainless was a real chore!
https://dynacotubeaudio.forumotion.com/t3126-vta-st-120-born-in-the-uk
In hindsight best for it to be to one side and move the speaker terminal? Not going to do it as cutting the stainless was a real chore!
https://dynacotubeaudio.forumotion.com/t3126-vta-st-120-born-in-the-uk
peterh- Posts : 1869
Join date : 2012-12-25
Location : gothenburg, sweden
Keeping the input jacks on the front will keep the leads as short as possiblepichacker wrote:I moved my RCA's to the rear (see my posts) and the only observation I can make having fitted mine centre rear is that the mains transformer has a large magnetic field and this can easily induce hum onto the input leads.
In hindsight best for it to be to one side and move the speaker terminal? Not going to do it as cutting the stainless was a real chore!
https://dynacotubeaudio.forumotion.com/t3126-vta-st-120-born-in-the-uk
inside the amp, and give the maximum distance from the power transformer.
sKiZo- Posts : 1530
Join date : 2013-04-01
Location : Michigan USA
If you do decide to move the jacks, you can minimize any chances of interference by twisting the wires. Solid core works well for that, as it keeps it's shape. Just chuck one end in a vise, and the other end in a drill and give it a spin.
Also not a bad idea to try and route the wire as far away from the iron and such as you can. The extra length shouldn't hertz.
I'm told it helps to also include a third "drain wire" with each channel pair. Let one end float, and attach the other end to common ground. Theory is, this wire should collect any stray nastiness that could impact sonic purity.
PS ... I knew I could fit a pic of the Monarch in this thread!
Also not a bad idea to try and route the wire as far away from the iron and such as you can. The extra length shouldn't hertz.
I'm told it helps to also include a third "drain wire" with each channel pair. Let one end float, and attach the other end to common ground. Theory is, this wire should collect any stray nastiness that could impact sonic purity.
PS ... I knew I could fit a pic of the Monarch in this thread!
Last edited by sKiZo on Tue Jan 10, 2017 12:53 am; edited 1 time in total
j beede- Posts : 473
Join date : 2011-02-07
Location : California
sKiZo wrote:
[cut]
I'm told it helps to also include a third "drain wire" with each channel pair. Let one end float, and attach the other end to common ground. Theory is, this wire should collect any stray nastiness that could impact sonic purity.
I always add a fourth "drain the swamp" wire. This is similar to the "drain" wire referenced above (near end grounded, far end floating). The terminations of the fourth wire are opposite--near end floating and far end grounded. This gives purer purity.
pichacker- Posts : 103
Join date : 2016-08-01
Age : 60
Location : Near to London - UK
Although the electronic engineer in me says that the twisted pairs above should not be used for interconnects in this situation as they are not connected in a balanced configuration.
But that's another topic for discussion elsewhere.
But that's another topic for discussion elsewhere.
sKiZo- Posts : 1530
Join date : 2013-04-01
Location : Michigan USA
?
They're connected in exactly the same way as the stock connections to the board.
By balanced, do you mean one running down each side of the chassis? That would have put one channel right on top of the PT. That said, any design will include some compromises - best I can say is it turned out dead quiet, so hey, I'm good wit it ...
PS ... can't say as I was all that concerned with maintaining the "correct" 8 turns per inch recommended (somewhere or other) for best results in the target frequency range either. ;-}
They're connected in exactly the same way as the stock connections to the board.
By balanced, do you mean one running down each side of the chassis? That would have put one channel right on top of the PT. That said, any design will include some compromises - best I can say is it turned out dead quiet, so hey, I'm good wit it ...
PS ... can't say as I was all that concerned with maintaining the "correct" 8 turns per inch recommended (somewhere or other) for best results in the target frequency range either. ;-}
corndog71- Posts : 840
Join date : 2013-03-19
Location : It can get windy here
pichacker wrote:Although the electronic engineer in me says that the twisted pairs above should not be used for interconnects in this situation as they are not connected in a balanced configuration.
But that's another topic for discussion elsewhere.
That's weird. I've seen twisted pairs for unbalanced interconnects as well as internal wire in probably hundreds of various types of audio gear. I thought it was fairly standard practice.