[satfrat]

Thanks Robin,
I'm totally stoked to get the 2.5.  I think I'll eventually get the custom z-sleeve for it, and the ERS material as well.  For now I'm just incredibly excited to hear what it can do in my system. 

Well you've already heard Mike's system so you've already got a clue. There's a lot of things you can do to tweak a BPT and thanks to Wayne, I've done quite a few. I first had my BP2.5 totally cryoed. I have 2 large Bybees inside after the transformer, Wayne built me a duel Bybee 20A IEC adapter for the front that plugs into a Ridge Street 20A Z-der Block (voltage reclocking). I use a BPT L-9 Litz PC that has an Extra Heavy Z-Sleeve on it. I also pu tan Oyaide P-079 gold AC plug on the end to better match up with my Furutech fl-20 gold duplex on my dedicated circuit. Inside the BPT, I had DynamiCaps installed on the duplexes for isolation and I installed supershields on the tranny shielding, wires (not the bare silver wire of course) and on all the casing. The supershield consisted of alternating layers of ERS and heavy duty adhesive aluminum foil. I used electronic grade RTV Silicone to seal everything. My unit sits on a Mapleshade Isolation System like the one in this picture.


I know how you like overkill so I just thought you'd enjoy my little bit of maddness.

Cheers,
Robin

[satfrat]

Tyson (or Mike), do you feel that further tweaking of the bias will be needed as you gain some hours on this system or is fluctuation on nonissue? Just curious.

Robin, I think it will be pretty stable. They used 15 turn pots, so I was able to set it very precisely but things do change over time and it will drift but I suspect that will not occur for a while, at least I hope so as those amps are pretty awful to move around.

Yea, we aren't getting any younger, are we Mike?

[Tyson]

No, we ain't.  You should see the bruise on my arm from moving my cabinet around.  Since the cabinet is too narrow to load anything form the front, I have to move the whole thing away from the wall before I remove any gear from it.  It's HEAVY with the audio-gd equipment.  I look like a junkie that missed a vein and bled out internally, seriously.  Of course being on plavix from my heart attack 2 years ago doesn't help....

[satfrat]

No, we ain't.  You should see the bruise on my arm from moving my cabinet around.  Since the cabinet is too narrow to load anything form the front, I have to move the whole thing away from the wall before I remove any gear from it.  It's HEAVY with the audio-gd equipment.  I look like a junkie that missed a vein and bled out internally, seriously.  Of course being on plavix from my heart attack 2 years ago doesn't help....

Getting old sucks for sure Tyson. I just got my blood test results back and my fasting sugar level was 387 and my A1C was 17.6. 6 months ago, it was 160 and 8.2 and the dr wanted me to start taking pills then so I expect I'll be either taking pills or insulin after Monday's Dr app. I've been a diabetic since I was 45 but it's always been diet controled. Not anymore. But I'm still well preserved on the outside.

Maybe you should have stuck with tubes? aa

Cheers,
Robin

[Tyson]

Updated with new info in the "Postscript" area.

[8140david]

Nice review, Tyson!
These products seems very interesting.

I have some questions.

How hot does your amplifier run? The radiators do not seem very big on the images.

And you're not worried about how long the composants inside will last, which such a power in class A?
Still happy after a few months?

Do you turn it off at night? If so, how long would you say does it take for the amplifier to reach its full potential when turned on?

And have you compared it to other amps? Likewise, have you compared the Dac8 to others?

[8140david]

I have another question.
You write:
"Output is 250 watts at 8 ohms, 500 watts at 4 ohms, and 1000 watts at 2 ohms. It's biased into class A pretty heavily, a little over 40 watts pure class A at 8 ohms, 80 at 4 ohms, 160 at 2 ohms."
How do you know that it's "a little over 40 watts pure class A at 8 ohms"? What does it mean exactly? Did you somehow measure it?

[Tyson]

Nice review, Tyson!
These products seems very interesting.

I have some questions.

How hot does your amplifier run? The radiators do not seem very big on the images.

And you're not worried about how long the composants inside will last, which such a power in class A?
Still happy after a few months?

Do you turn it off at night? If so, how long would you say does it take for the amplifier to reach its full potential when turned on?

And have you compared it to other amps? Likewise, have you compared the Dac8 to others?

Hi,
The amps do not run particularly hot anymore, I can rest my hand on them for more than 30 seconds before I have to take it away due to heat.  At first they were biased too far in to class A, probably close to 100 watts, but now I've got them down to between 35 and 40 watts and it's runs no hotter than many other solid state amps I've had. 

I'm not too worried about components - the Nover caps and the Toshiba output devices are all available on the free market, so even if audio-gd goes out of business I will be able to fix any problems.  The only parts are the CAST modules, which might be a problem if audio-gd goes under, but I will likely buy a couple of them for spares just in case.  Since they are modules, maintenance should be very easy. 

I do turn them off at night, but mainly because I am trying to minimize how much energy I use, I'm trying to be more responsible for conserving and having less of an impact on the environment.  I would say that they sound good after 30 mins, very good after about 60 minutes, and the absolute best after 2 hours. 

Am I still happy? Yes, I'm even more happy now than ever.  I had swapped my C1 amp to do bass duties only on my VMPS RM40's for a long time, and had bought some VTL tube amps for the midrange and highs.  I recently swapped the C1 back to full range duties and was amazed at how they sounded all over again.  So much so, that my VTL amps are now up for sale on audiogon.  The preamp is the best solid state preamp I've ever heard.  The C1 is also among the very best, and the DAC8 is the most detailed DAC I've ever heard as well. 

I've reviewed and been exposed to a ton of different different equipment, just do a search on my username on this site. 

Finally, for bias settings, once you pull the cover off the C1, you can set the bias to anything that you want, there are 4 pots that let you change it to almost any value.  I decided on 35 to 40 watts since that keeps it in full class A for most music listening, but still keeps the heat quite low. 

I would say that the heatsinks were too small when the amps were running (incorrectly) at 100 watts class A, but are more than adequate for only 40 watts class A.

[8140david]

Many thanks! That answers my questions 

The only remaining worry is the noise issues you had.
It would be troublesome to face similar ones.
But some of them, if met, should be rather easily fixed (even if it adds to the total cost): cables and a clear power supply.

[Denis]

Thanks for the review on the Audio-GD amps. I've become very interested in this company since purchasing a large amount, almost 200, discrete op amps from them to upgrade the circuitry in my recording studio. I was extremely impressed with the company both in quality of goods and in customer service. The owner, Kingwa who designs and operates the company was extremely easy to work with was very responsive to any questions I had and if there were any problems or issues immediately took care of them professionally and politely.

As far as his discrete op amps- I compared all three he had available, Earth, Moon and Sun, in a preamp circuit that originally used NE5532's which I had a upgraded to Burr brown opa2432's (if i recall correctly). I remember feeling as though the upgrade from the NE5532's to the Burr browns was a huge sonic advance in terms of clarity and focus. It seemed to lift a layer of crud off of my mixing board.  But the upgrade from the IC to the discrete op amps was immense. So much more head room and detail and a trueness to the source that the IC's did not approach.

I a-b'd the 3 audio-gd op amps. I was using a coles 4038 ribbon mic as a drum overhead into my Hill audio mixing board. I always found this mixing board to be somewhat middle of the road set up with the ic's. However with the discrete op amps it really came alive.

The Earth op amp to my ears in this circuit although a massive improvement over the ic's did not capture the sense of depth to my drum kit that the Sun or Moon op amps did. The high hat sounded thin and you did not capture the sense of the woodenness of my vintage Ludwig maple snare. It was very quick though. It also seemed to lack a thickness to the bottom end that both the moon and Sun had.

The Moon op amp indeed sounded more tubelike. It had a softer more rounded quality. A pleasing overall tonal quality but to my ear wasn't as quick as either the Earth or Sun. A really great overall sound though.

The Sun op amp. This is the one that really blew me away. Everything from the highest cymbal crashes to the lowest, loudest kick drum strokes sounded balanced, present, with a sense of depth and quickness with a beautiful round sweetness to it. I could hear all the detail I wanted out of the snare rattles. You got a nice 3 dimensional sense from the kit. You can hear the cymbals waving about and shimmering.

I was totally sold on these. I ordered in 3 large batches and proceeded to upgrade different boards and amps that i could with the op amps. Some of these of course required power supply upgrades but it was worth it.

In any case my orders from Audio-GD came extremely quickly. The build quality of the op amps are very high and like I said the customer service is really unrivalled. Kingwa seems to be very responsive to aesthetic of his customers. From what I gather he has a lot of respect for the ears of those he is designing for and  delivers a product that satisfies his most critical customers.

Anyway, I appreciate Tysons review as I have been looking into purchasing some of his stereo amps and DAC's. I actually should be receiving his DAC-Headphone amp-preamp in a few days. I look forward to that.
I'm hoping this company continues to grow. He seems to be releasing new products all the time which is a good sign. I know that these guys are all the way in China and that causes some logistical problems with servicing and they are a young company but I feel like these guys are worth taking a chance with. I really appreciate Kingwa's audio aesthetic, his deference for the customer, Audio-gd's high quality production and tremendous value. I'd like to see more reviews of their products if anybody's got them.

Denis

[richidoo]

Welcome to AC Denis!

It is rare to meet a true audiophile also a pro audio engineer. You got it really bad, just as much a perfectionist as any normal 2ch audiophile, but you have 48+ channels of board, probably as many outboard, and everything is balanced! It takes special dedication...  Right on!   
Please PM me the name of your studio. Thanks
Rich

[santacore]

It is rare to meet a true audiophile also a pro audio engineer.

 

Make it two of us, although I'm actually a Post Production mixer. As much as some of my colleagues laugh at me, I love my audiophile gear.

As for the Audio-Gd gear-I picked up a C-2C headphone amplifier from Kingwa about a month ago. The whole experience was very good and amp has exceeded my expectations in every way. Now it might not be the final word in head amps, but it smoked everything I've heard near it's price(and I've owned quite a few). The highest compliment I can give it, is every-time I sit down to listen, I get so drawn into the music that I forget to analyze the amp. It's musical, it's dynamic, and detailed. I'm so impressed by this piece that I'm actually considering trying one of his higher end dacs and possibly even an integrated. Check out the Audio-Gd offerings, I'm think you'll be impressed like I am.

[Denis]

Hi Guys,
Being an audiophile and an engineer is a ridiculous combination but add being a musician on top of it and I simply have no money to eat at restaurants outside of the Taco Bell value menu. I don't make my money from engineering though. I use my studio for my own projects as well as other bands and individuals whose music I like. But it is an audiophile analog studio and it is quite something to maintain. I don't know if how many of you know what some vintage Neumann tube mics goes for these days but you can buy a decent used SAAB for less.

It strikes me as funny that anyone would poke fun at anyone involved in the audio arts that loves audio- I mean isn't that what it's all about? Yeah and those hi end DAC's that Audio-GD offers caught my eye also. It would be nice if Kingwa designed some high end Analog-Digital converters for use in recording. My guess is he could make a killer converter for a fraction of the cost of what is on the market now. The fact that his stuff is so price effective is why I tried his op amps to begin with. Thank god i did. I mean my recordings now sound so much more real and the *feel* of the music is there like it never was. I mean my drums now not just sound like my drums when I'm sitting behind my set but they also, on playback, impart the nuance and emotion that I was feeling when I was playing.

Denis

[av_passion]

My system is actively bi-amplified so this involved resetting the gain settings in my crossover (modified DCX2496) to match the Audio-GD to my other amp. We ran these on the top end with the little Rotel 1080 on the woofers. While it sounded good it wasn't what I thought it should be. We then configured the system with both Audio-GD amps so they were feeding both the low and high sections of the speakers. To do this we had to remove the C1 (I think) module so we only had 6dB of gain from the amps thus limiting our volume but the resulting sound was exceptional. Both of us were pretty stunned, particularly on the bass.

Why did you have to remove the C1 module (I presume that you are referring to the pre-drive amp component, to use a term from the GD-Audio website) as I thought the C-1SE was designed to support bi-amping?  Does it conflict with the Behringer in some way?  I would have thought you would feed the signal from the pre-amp to the Behringer to the pre-drive amp component to the output drive amp.

Lastly, were you bi-amping the Geddes speakers?

[JDUBS]

Why did you have to remove the C1 module (I presume that you are referring to the pre-drive amp component, to use a term from the GD-Audio website) as I thought the C-1SE was designed to support bi-amping?  Does it conflict with the Behringer in some way?  I would have thought you would feed the signal from the pre-amp to the Behringer to the pre-drive amp component to the output drive amp.

Lastly, were you bi-amping the Geddes speakers?

Dude, you're replying to a post from almost 2 years ago!

-Jim

[av_passion]

Don't I know it and I debated as to whether or not I should reply but Tyson's review is the most most comprehensive review of Audio-GD equipment that I have seen and covers most of the components in which I am interested. 

Furthermore I also plan to acquire Geddes speakers soon and I know Mike Galusha has or had Geddes speakers in the past.  Another friend of mine has them and bi-amped them and said he would not go back to a passive crossover.  Between Mike and Tyson they have (or had) almost everything I am considering and in a configuration that I would like... so I thought I might as well ask even if their comments are 2 years old.  Beside, if Tyson still likes his equipment then I know it is good.

[Tyson]

I'm putting my c1 up for sale

[av_passion]

So what are you replacing it with and how much are you asking?  (maybe we should PM)

[Tyson]

I've moved to open baffle speakers, and they need amps that have a built in EQ boost in the lowest bass regions, and also a rumble filter built in to prevent over excursion of the woofers, since they operate in open air.  If you are really interested in the C1 (which is still the best SS amp I've ever heard), shoot me a PM.