Garage 1217 Project Sunrise III measurements

Original Post by atomicbob

This hybrid tube - mosfet ampifier has been providing me with considerable enjoyment for some time now. Here are some measurements I made today in a quest to dig deeper into why this amp sounds so good to me. The distortion is particularly good considering the low voltage plate tube front end and the no feedback topology. The listening station is a Mousai MSD192 (measurements found here), the PS3 and HD6x0 or D5000 headphones as the cans with most audition time on this system. I should think there would be more discussion of this amp given it has an exceedingly high performance/price ratio.

The data presented were collected as follows:

1. PrismSound dScope III, picoscope 5243B
2. DAC unbalanced output RCA
3. 100 Kohm load used for measurements
4. 44 KHz sample rate, 24 bit depth
5. USB input – Audioquest Forest
6. Unbalance cable DH Labs Silver Sonic Air Matrix RCA
7. Vaunix Lab Brick USB hub
8. PS Vane 12AU7 used in PS3
9. PS3 output set for 32 ohms

Picture of the Kitchen Counter Audio Lab

Tests were run at a gain consistent with my personal listening sound levels which is between 70 to 77 dBC SPL.

A 0 dBFS sinusoid at that gain is 700 mVpp:

There is a 1 dB imbalance between the channels at my preferred listening level. Not enough to concern me for recreational listening.

Square waves can reveal a lot about an amplifier's performance. For reference morphology, the signal generator waveform looped back to the oscilloscope input at 1 KHz, 700 mVpp.

Signal generator loop back to oscilloscope input for reference

PS3 square wave 20 Hz 700 mVpp 10 mS / div 100K load

PS3 square wave 20 Hz 700 mVpp 50 uS / div 100K load

PS3 square wave 20 Hz 700 mVpp 10 mS / div 50R load

PS3 square wave 20 Hz 700 mVpp 50 uS / div 50R load


Noting the Mousai MSD192 has an excellent 20 Hz square wave response and so too the PS3, we have a theme developing.

 

Original Post by atomicbob

Part B of measurements.

Here are 20 Hz square waves with an HD650 as the load:

PS3 square wave 20 Hz 700 mVpp 10 mS / div HD650 load

PS3 square wave 20 Hz 700 mVpp 50 uS / div HD650 load

dScope measurements

PS3 amplitude - phase - gain

PS3 signal to noise

PS3 THD+N THD nth harmonic distortion

Three things to note about the distortion measurements.
1) Distortion will be dominated by the tube chosen for the input gain stage.
2) The 3rd harmonic distortion is 20 dB lower than the 2nd harmonic distortion. My ear finds even harmonic distortion pleasing and odd harmonic distortion offensive. Thus the PS Vane 12AU7 is behaving the way I prefer in the PS3.
3) The PS3 does not use feedback to lower the distortion specs

editorial - I believe there is a tendency to focus too much on THD numbers rather than look at distortion spectrum and type such as even vs odd in an attempt to reduce a complex topic to a single number representing a sort of goodness rating.

 

Original Post by atomicbob

Part C of measurements




If you made it through all of the numbers and graphs, you can see why I think this hybid headphone amp rocks.

 

Original Post by atomicbob


Quote from: Solderdude on May 25, 2015, 10:55:40 AM
"The amount of distortion greatly depends on the output level.
The lower the output level the lower the distortion.
At 'Normal' listening levels the THD levels are considerable lower b.t.w.An excellent point! The dScope measurements were performed with a -1 / -2 dBu output. I tend to listen with a level averaging -10 dBu or less. I should reprogram the dScope amp scripts to allow a lower reference and repeat."

Tube dependency allows tuning amplifier character to suit one's tastes. It also makes comparison of notes between listeners a little more difficult as they need to discuss which tube was used that gave them the sound they heard.

I did not put up the crosstalk measurements as I found considerable variance depending on the cable used for TRS to stereo RCA for connection to the dScope input. The least expensive Radio Shack performed much better than a major name high end super duper TRS to stereo RCA cable, for example.

 

Original Post by atomicbob


Conditions:
1. PS Vane 12AU7
2. PS3 32 ohm output setting
3. 50 ohm load
4. 4 Vpp input from signal generator (+5.23 dBu)
5. 600 mVpp output from PS3 into 50R load

Frequency Response

-0.5 dB 3 Hz to 70 KHz
-3.0 dB 1 Hz to 200 KHz

10KHz and 100 KHz square wave response
top trace - signal generator input
bottom trace - Project Sunrise III output

10 KHz square wave response:

100 KHz square wave response:

100 KHz square wave response x-axis zoom:

 

Original Post by atomicbob


Quote from: Solderdude on September 14, 2015, 03:56:34 PM
"In SR/Horizon the gain is determined by the tube used and there is NO overall feedback at all."

This is one major reason that I find Project Sunrise III so special in sound.

 

Do you find this beauty has the power to drive the Sennheiser HD650 with classical music?

Once I've recovered from my Master-11 purchase, I'm going to look back into tube amps.

I love the Polaris and Ember, but I'd really like to get an OTL amp that works with both of my main cans (64 Ohm JVC HA-DX2000 and 300 Ohm Sennheiser HD650).

2 years later: Don't love Ember, do love Sunrise and Horizon.

 

thanks for this instructive and remarkable thread ....

 

It has sufficient power to drive all of my high impedance cans, HD650, HD800, T1, T90 with the dynamics befitting of classical music. Keep in mind that I listen typically 10 dB SPL lower than most. Therefore my ffff is 110 dB SPL at most, more likely 100 dB SPL. An example of a very dynamic recording is Reference Recordings HR-70 Firebird Suite. The Project Horizon has been optimized for higher power with high impedance headphones. I have yet to feel I need higher power than what Project Sunrise delivers. I also have found that I prefer an Electro-Harmonic 12BH7 at this time. Very quiet tube, current production, $22 US.

 

Awesome. I might put this on my list, then. It's much more affordable than other tube amps I've been looking at, Jeremy is awesome, and they look amazing.

I also tend to listen at lower levels than many because I listen to music for 6-10 hours at work.

 

Very wise to run lower levels for such long listening sessions. Your ears will have a better chance to last you a lifetime.
Look here for my thoughts on how this fits into a very nice system, what I consider the low end of reference systems:
http://www.superbestaudiofriends.or...tem-synergy-special-sound.54/page-3#post-4895
Also check the very first post in that thread.

 

Nice. I've had pretty much that exact setup with a Regen instead of linear psu and Ember instead of Sunrise. Different tube, same cables.

I'll probably end up basically right there for my work setup unless the Soekris dac1101 beats the Bifrost Multibit.

Only sold it because I really wanted a Master-11 at home and had some other expenses to take care of.

 

Sunrise in the house! Along with the Electro-Harmonix 12BH7 Gold Pin @atomicbob recommended.

So far, super impressed!

I like it even more than the Ember at first listen. That said, I never got to hear the Ember out of the Master-11's DAC section, nor did I have the same tube.

What a lovely sound!

I might be slightly disappointed tomorrow when I use it at work with an inferior DAC, but this should complete the amp section of my endgame work setup.

 

Forgive me if I'm wrong but I think all G1217 amps are hybrids, with the Polaris as the only exception?

 

yes, they are intelligently designed hybrids. The Project Sunrise is getting a lot of air time tonight.

 

Gawd after years of Thujone recommending Garage 1217 to me I finally demo'd the Starlight [Shame on me for picking the cheapest one... drat]

I wound up purchasing it... then dropping $80 into some tubes q.q why I still feel my HE 4 sounds BEST Solid State, my LA D5k SIIIIIIIIIINGS out of the Starlight! with all of the Lawton Mods it's mids get even drier an taken back... so the Starlight really just balances it out nicely!

I talked a LOT of schiit about the Garage 1217... like an idiot. An now I own one! 9/10 as soon as they put out a balanced Hybrid Tube I'll but it too

 

Glamour shots of my Sunrise III, including the new CNC aluminum chassis I just put on it today:

 

I spent four nights with an Atlantis going into a Project Ember II. It's a lovely combo.

When I got to work today I plugged into the Sunrise III.

Something about it is just more romantic.

I have a Horizon on the way to compare it to the Ember and I suspect that's what I'll end up with at home.

 

Curious to hear your thoughts on that comparison! I finally got the Ember my self [I was planning to get the Sunrise III originally] I'm curious how the Sunrise compares to the Ember II

 

Honestly, the Sunrise III and Horizon III are pretty much equal. They're largely the same but for different impedances.

I did a review a while back: http://www.basshead.club/garage1217-project-ember-horizon-sunrise-review/