Audio Science Review = Rebuttal and Further Thoughts

@kota1 You’ve done a very impressive job correcting your room sound from the speakers alone (quite bumpy). Looks really flat after correction.

Back in the mid-1980s, I was fortunate to hear Conrad Johnson’s top pre-amp (don’t remember the name), an Audio Research SP 8 and an SP 10 (I don’t remember which of the 7 versions). I was amazed at how dark and closed in sounding the CJ pre-amp was, even compared to my highly modified Dynaco PAS--3. The SP8 was just as warm sounding but the soundstage was so much larger, more open. The SP10 blew me away. Great soundstage, 3 dimensional sound and wide frequency response. I couldn’t afford and it uses a lot of tubes.

A year later I acquired a Fisher 400 CX tube preamp for free from an estate. It sounded almost as good as the SP10, a little darker and less open. Musically it was great. I sold it for a nice profit. At the time, I didn’t realize how good it would be even today but my tech guy back then said his Dynaco was "purer" sounding.

I have heard since the 80’s maybe 4 CJ preamps and at least 5 CJ amps. My neighbor had the CJ Art 27A running into the tweeter and mid of a YG Sonja 2.3. It sounded lovely on small ensembles, voices and non-percussive instruments. He has a PS Audio BHK 250 amp for piano, rock and orchestra/opera. Well the CJ sounded very warm with lesser resolution than the BHK. The latter has NOS input tubes and has a dynamic and wide open sound although not ideal for voices. So, he has two separate sounding amps (sold the CJ, bought a highly modified Dynaco ST 70) in a tri-amped system (bass and subs have big Class D amps). He listens to music on each amp dependent on the type of music. This appears similar to prof choice of using the clean and clear wide open sound of the Benchmark L4 and the more seductive, warm albeit more distorted sound of the CJ preamp. That’s an easier choice than maintaining separate speakers/rooms to do the same.

Luckily, I have cool running Class A/B 125 watt voltage regulated monoblock tube amps that play anything and most speakers (I haven’t tried them on impedances below 2 ohms but they will play well with 85 db speakers). The funny thing is that my 2nd system amp, a voltage regulated highly modified Dynaco 70 35 watts has great control versus my back-up to the 2nd system which is an EAR 890, a class A zero global feedback, super heater/hot running 70 amp which can’t control 3 12" woofers per side. Sounds great on the Signature IIIs 3 10" woofers.

I own two other DACs purchased when I switched from the EAR Acute (2005), the COS Engineering D1v ($9000) and D2v ($5000) retail. They are gorgeous units which even my cable/equipment manufacturing friend says are also exceptionally built. However, they have a 1 second delay algorithm which blurs and expands the sound and a bypass which is relatively dry sounding.

The D1 is like the Benchmark L4 to a great extent. It is so clean and clear in bypass mode with wide frequency response, wide soundstage, dynamic. BUT-it lacks 3-D quality (minimal depth) and has a sort of sterile sound (missing body but great tonal quality). This is what it also sounded like on 3 other systems and none of my friends liked it compared to the D2v which has only a single linear power supply, single transformer, etc. compared to the beautiful D1v. It has a warm, lush sound like a CJ pre-amp. It has more limited bass and rolled off highs, less open but oh so sweet for voices and acoustic instruments. I intend to sell both now as I bought the super modified Benchmark HDR1 DAC which obliterates those two DACs and sounds like 5 figure DACs like my friend’s Ultradac ($23K), maybe better. Cost-$800 for a clean used unit and $800 in parts and labor.

P.S. I tried a dozen different transports on the COS units. The Benchmark sounded better on the three I kept by a mile. The COS units had the same sound profile on ever transport, the Benchmark shows the significant differences.

@axo1989  I've been collecting/listening to LPs for 60 years.  Digital playback has evolved to be tremendously captivating, often equal to the best vinyl.  Unless there are some performances/music that you find you can only obtain on vinyl (about 30-35% of my collection), you might prefer putting all your eggs in the digital domain.  Also, analog is not as easy to use and maintain but you probably know that. 

Same with CDs versus streaming.  At least half of my CDs will never show up streamed (1000+ private label vocals, violin and piano CDs) and many of the other 50% are not presented in as good mastering on-line.   

holmz , I thought everyone here knew how the virtual systems page works, my bad :).

It’s OK - I believe that it works different on an iPad than a computer browser.

As for measurements, I am not against measurements, I thought posting them would be interesting if we are discussing measurements any way right.

Correct.

I found Amir’s many considered comments very informative and valuable. And now they are all forever gone at the whim of AG.

This has happened many times before on this forum.

…

Yep - It is hard to see and witness thoughtful threads, albeit with some divisiveness, get deleted out of hand… seemingly on a whim.

@fleschler

However, the older DACs can be upgraded to have that 3 dimensional, full bodied and warmer sound with modification of parts. The engineering is sound as is the basic construction.

I didn’t know that. You have previously commented on a recently deleted thread on how components (eg, an amp made by Benchmark) may be upgraded from stock, and this is always intriguing.