The 'Ultimate' $500 HiFi Amplifier UPGRADE

Dynaco ST70 is a vintage HiFi audiophile tube amplifier that is regarded as one of the best, selling thousands since its release. They don't make them anymore but the love still goes on with these Upgrades!

Related Videos:

0:00 RECAP on Dynaco ST70
1:47 Dynaco ST70 Upgrade: Miller Audio
6:13 Dynaco ST70 Upgrade Sound Review
10:12 HOW MUCH POWER?
12:03 WHAT'S THE PRICE?
12:35 BEST Vintage Amplifier Binding Post Adaptor!

#hifi #audiophile #vintage

[Jayiyagi]

*Who loves their Dynaco ST70?!*

Related Videos:



0:00 RECAP on Dynaco ST70
1:47 Dynaco ST70 Upgrade: Miller Audio
6:13 Dynaco ST70 Upgrade Sound Review
10:12 HOW MUCH POWER?
12:03 WHAT'S THE PRICE?
12:35 BEST Vintage Amplifier Binding Post Adaptor!

[marksmusicobsession]

Tube rectification is one of the many reasons I love my McIntosh MC60’s

[tonys.]

Great review Jay!

I have one of these upgraded amps and I can truthfully say it is the best sounding amp I own. I know Bryan personally and think he is a brilliant engineer, no bias intented (excuse the pun). First, by responding to a local add for a restored Fisher X100, then picking up some monoblock W4s, Maggies, Dynaco MK3, etc... His ST70 is in a league of its own. I've heard and seen the progression of this upgrade and it is truly a remarkable amp.

Your review is spot on in my opinion, that it retains the tube amp magic while having an accurate bass response, power and authority by the improved rectifier circuit. The amp is super quiet too and stable. He showed me on a distortion analyzer they operate something in the low hundreths of a percent and other improvements to lower the noise floor.  

For me, it is the best of hifi. A tube amp where important and SS in critical places outside the signal path, check out all those filter caps! The preamp section is improved. I prefer the 6sn7 as opposed to the smaller driver tubes.

[DougMen]

The most iconic stereo amp ever, designed and built by the man that invented Ultralinear tube topology, David Hafler.

[OddAudioCanada]

The main difference between SS and tube rectification is you can run way more filter capacitance with SS - with a tube reg, you are limited to a modest value due to the inrush current and need chokes (inductors) to smooth things out. Modest = 20-60uf for the first cap depending on the tube - that ain't much! Too much inrush when the caps fill and it will kill the tube. Plus there's a limit to how much current can pass through the tube so it can limit the potential power. So for best results SS then a bunch of capacitance to get a stout power supply. If you design around SS from the start you have next to no voltage drop and can run higher B+ voltage for a little more power (the drop in SS cans have a built in voltage drop to match the voltage of the tube they replace).
If the Miller Autobias is based on the AB-Q modules (which it appears to be) it's a great system, I've used them in my homebrew designs. Set and forget and built in warmup mute.

[carlostmartinez]

Exactly what I said to Bryan Miller. It maintains that middle frequency “Magic”, with better bass control and extension. The soundstage is better exhibited! It’s all about the music!

[stinkenstine]

I went with a totl Kenny Russell version. All new components using the original David H. Circuit. All caps are as good if not better than McIntosh. He lets you choose. Blows all of the other’s out of the water!

[christianbolt]

I have the Dynaco MK III monoblocks and upgraded all the components. Still may make more upgrades. Love the sound, made me fall in love with tubes.
Don’t need more power as I have VTL 450s for that

[WigandKleine]

Hi Jay; I saw the MP-DX on your stack; do you plan reviewing it? Would be nice

[psyphonyxaudio]

Awesome! - I've been interested in doing some DIY stuff for a while. Orchard Audio was one of the first that I recall offering kits .. but this one .. This seems special.
Great video also .. " Kidney? " haha.. Got me on that one. =)

[peterlundskow]

I have an updated one but not Miller version, thanks for the video!

[mikewolfe]

Nice! Thanks for the review. I’ll be at the audio fest, so I’ll make sure to check these out.

[JC.LC.]

Solid state rectifier is the way to go. More slam less sag....

[jankilly]

I have a Bob Latino redesigned ST-70 driving Quad ESL-57. OMG !!! In heaven. An excellent first tube amp w/o breaking budget. “OTL” amps are supposed to be the cat’s meow, but $$$$

[terryhu]

I have the Vincent SV500 with my Tekton Lores. It’s a modern 50 watt class a/b with a tube preamplifier. Unbelievable

[Rooooarzzz]

What about the Nat Transmitter tube amp we see on the video, are you going to do a review on those ? This would be interesting

[fletchermunson]

Early in my audio hobby I was lucky enough to come across a pair of upgraded Dynamo MkIII mono tube amplifiers. They were amazing but like a fool I let them go and have never seen a pair again. Big mistake!

[Alan_Always]

Jay - my question is how does the Miller sound against the "get dynco" or the Bob Latino "tubes4hifi" upgraded versions of the ST-70? All three companies sell these upgraded clones but aside from the rectifier debate, I'm not sure what the differences are. I'm interested in buying/trying one of them but it's hard to make a decision of which one as they all get glowing reviews.

[francoisroberge]

If you're going to exchange a GZ34 tube for a WZ34 Copper Cap it would be wise to get a slow start if you don't want to fry the EL34s. SS does not warm up.

[DougMen]

There are still to this day very few transformers that can match the Acrosound and Dynaco transformers designed by David Hafler and his partner Herb Keroes. They are legendary.