[Dusty Chalk]

I have no idea how a TDS passive audiophile works. How can a circuit amplify a signal? That just doesn't make sense. Wouldn't that mean that if you put enough of them in series, you would be able to drive a pair of headphones...or speakers, for that matter?

 

[Hirsch]

Quote:

Originally posted by Dusty Chalk (Sorry for the delay, been working on my taxes.) - Hirsch has way too many DVD's. (And no anime!) His collection of the ones he hasn't watched yet is bigger than my entire collection, I believe.

No anime? OK, it's not the largest part of my collection, but I've got at least ten or twenty DVD's worth. Finding them buried in there is another matter. Hmph.

Quote:

- I need to either (a) have his job/income, or (b) be his credit card company.

Definitely the latter.

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- Loki (?sp) has got to be the nicest cat I've met in a long time.

He was born feral, but decided he liked it here. He tried acting feral when I first got him, but he also found out that he liked having his belly rubbed. So, he gave up being feral in a hurry. He also has to be in the middle of anything going on in the apartment. His brothers are more reclusive.

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- I need to get a pair of those Silver Lace interconnects. They were easily some of the finest interconnects I've ever heard. - The ART DI/O did not best the MSB. To my ears. However, at 1/3 the price, it comes pretty damn close. Close enough that, had I known about it at the time, I probably would have saved a few hundred dollars. But as it is, since it's money already spent, I'll stick with what I have. It's not a giant killer, but it is definitely a better bang for the buck. I would think of it as the Sony V6/7506 of DAC's -- I.E. a great entry-level upgrade (not the sound, mind you, just the frequency response).

The DI/O's are getting there. Next step is to rebias one into Class A operation, and upgrade all of the resistors in the signal path. If I'm up to it, I'm going to substitute output transformers for the entire analog output stage in another. Then we'll try again...

Quote:

- I finally know what people are talking about when they refer to the "Grado slam"! (I've only heard one set of Grado's in my life -- the 225's, I think -- and was too busy being distracted by the discomfort factor to enjoy them properly.) - Those HP-1's are the only set of Grado's that I have ever actually liked, and there were a lot of them there! (I guess I'm just not a Grado man.) - That RA-1 is nice. I take back everything I said about it. - I'm deaf. A lot of things were very close, yet audibly different. But in a lot of cases, I could not immediately tell the difference. For example -- WRT (what, to me, were) the big three amp's -- the RKV, the MicroZOTL, and the Melos -- they're all very good. At this point, it's not a matter of one being better than the other, it's a matter of which character you prefer. I'm pretty sure I chose the right one, as I am really happy with the character of the RKV in the context of Saturday's meet. The character of the Melos is pretty close to the RKV, I have a hard time discerning the two. However, the MicroZOTL was very different. - Another example of deafness -- could not tell the difference with the phase switches on the HP-1.

The phase switches only seem to matter on rare recordings. I used them when I first got the HP-1, but I'm tending to forget about them more and more.

The RA-1 quietly goes about the business of playing music. It's easy to overlook just how well it can do that. Although I did some more listening to the HP-1 afterwards, and the RA-1 really didn't have the power to get bass out of them, IMO. I actually prefer the RA-1 with the HD-600 over the HP-1, for that reason. The RS-1 sounds good to me with the RA-1, but so does the SR-200, and the RS-1 IMO is not worth the extra money.

I guess I'm deaf too. There were a lot of things that should have sounded different, but didn't. It's all a matter of time, I think. An afternoon is way too short a period to get a handle on a good piece of equipment. I didn't spend time with the Melos on Sat (I can hear it anytime), but that RKV impressed me. It's a clearly different sound from the ZOTL, but it does indeed become a matter of preference. The "big three" all have very distinct personalities, and it's a matter of finding the one you like. There's no point in saying one is better than another...IMO they're all at a level where "better" is meaningless. The ZOTL has become my primary headphone amp, and I'm still learning its personality, long after I've stopped rolling tubes.

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- I need to remember not to forget anything next time. I didn't bring any tunes, other than my Keith Jarrett Sun Bear box. So, no dark music for Hirsch. - I forgot my Cheesy Poofs. Oh, well, enjoy them Hirsch!Not likely -- the Headroom thing is in mid-June -- see you there! But we will have others. I know I'll be stopping by Hirsch's again at some point...

And me doing Weight Watchers. I think I'm allowed to eat two Cheesy Poofs a day.

Once things got started, I didn't get a chance to go into my collection and find interesting things to listen to. Next time I'll be more prepared...

 

[Dusty Chalk]

One more thing I came away with (besides cat hair) -- the "Smurf" blue MicroZOTL is not as ugly in person as it is in pictures. It just does not photograph well. It looks a lot less "ghetto" (as someone else in another thread referred to it) in real life.

 

[shivohum]

Hirsch, Dusty, and anyone else who attended: what are your takes on the sound between the HD600 & the HP-1? And which pads was used on the HP-1? Thanks.

 

[Dusty Chalk]

Well, I'm not a Grado guy, but...man, I tell you whut, I need to get a pair of those (referring to either the HP-1 or HP-2). I have been finding the Sennheiser to be a very accurate and detailed phone, but just a tad laid back in its presentation lately. Those HP-1's sounded good on anything, though, even the RKV (usually the RKV doesn't like sensitive phones -- raises the noise floor). Even the RS-1's brought out -- what I thought was -- the solid-state nature of the RA-1 compared to the HP-1's. But it was completely absent on the HP-1's, which tells me it was not the amp. Smooth smooth smooth, and accurate. And detailed. I have no idea what my long-term listening preference would be, but the comfort of the Sennheiser (sorry, just cannot get used to those awful Grado's) will probably sway me. But if they felt the same, I think I might go for the HP-1's.

Initial impressions.

 

[DarkAngel]

Great report guys, and nice photos.

Why do I get the sneaking suspicion that Hirsch is about to order a RKV amp.......hmmmm

 

[neil]

Cool meet -- very nice photos too. Great job putting that together. I can't wait for the next Head-Fi Detroit shindig. If Hirsch ain't comin', I'll bring the cheese.

 

[Hirsch]

Quote:

Originally posted by DarkAngel Why do I get the sneaking suspicion that Hirsch is about to order a RKV amp.......hmmmm

I think Hirsch has reached the limit on what he can spend on amps. However, should a Melos and a ZOTL simultaneously appear in the "Gear for Sale forum", something might be up...

<This isn't going to happen>

 

[Audio-Me]

make note, he hasn't heard the Cary yet.

kewl meet guys

 

[dhwilkin]

Hirsch, exactly what mods have been done to the DI/O? And what power supply is it using?

Also, I keep reading comments about the top amps having different characters. I know an afternoon is too short to really understand them, but would somebody try to describe the differences in character anyway?

 

[acidtripwow]

Looks like a cool meet. Yes, the Grado HP 1000 is a fantastic set of headphones. I have the HP2 version with reference cord and it sounds incredible paired with the RKV II amp.

 

[Hirsch]

Quote:

Originally posted by dhwilkin Hirsch, exactly what mods have been done to the DI/O? And what power supply is it using? Also, I keep reading comments about the top amps having different characters. I know an afternoon is too short to really understand them, but would somebody try to describe the differences in character anyway?

The DI/O's are using Sencore 9 vac 3.4 a power supplies.

Mods so far:
1) replaced 100 ohm digital input resistor with 75 ohm
2) removed output caps, replaced with jumpers
3) replaced Diodes with Schottky's
4) repaired damage to internal ribbon caused by above (eventually replaced with silver wire)
5) installed op amp socket. On DI/O uses LT1365 op amp, another uses LT1362. The 1365 has better specs than the 1362, but the 1362 is generally considered better sonically. I tend to disagree, and prefer the 1365. (Note to Dusty, the DI/O on the Rotel was the one with the 1365)
6) Replaced electrolytic capacitors in power supply
7) replaced resistors in analog output stage, attenuating output

On the DI/O with the 1362, I've also removed most of the tube circuitry. Next free time I get, I'm going to sit with the schematic and get rid of the rest of the A to D circuitry (maybe).

How to describe the sound of op amps? You can use electrical characteristics (I can't, but I don't have sufficient electrical training), or you can use the same vocabulary we use to describe amplifiers. We're talking about the same thing. In theory, the 1362 is supposed to be smoother with a fuller midrange, while the 1365 has a brighter treble and deeper bass. In practice, I think the 1365 has a better balanced sound all the way around, while the 1362 is a bit peaky (actually thin, rather than full in the middle).

 

[formulacarl]

It was good fun meeting up with Hirsch, dcg, Dusty Chalk and Harv. I had some serious allergies from the cats, but stayed the whole time anyways. I just couldn't get myself to leave. Thanks again Hirsch for having us over.
I am new to all of this and have not heard a lot of equipment, but I just have to say that the ZOTL sounds good and looks a lot cooler in person. In the relatively short amount of time that we had, it was difficult to really compare things. In addition to all the gear ( a lot of other gear wasn't actually on the table) Hirsch also supplied several cables.
Dusty Chalk and I used Kraftwerk's "Computer World" as our primary source for testing things out. (This automatically makes him cool

)
The Grado HP-1s sounded nice. After listening to the Beyer 770s I am convinced that they will be my next purchase in addition to an amp.

 

[dhwilkin]

LOL, oops, guess I should've phrased my last question better. I appreciate the op-amp comparison, Hirsch, but when I said "top amps", I meant the top headphone amplifiers at the meet (RKV, MicroZotl, and Melos). I'm especially curious about the "character" of the RKV, and if a raised noise floor was noticeable w/ any of the low-impedence headphones. BTW, how much difference do you feel changing the power supply made to the DI/O's sound, as opposed to the internal mods?

 

[Hirsch]

Quote:

Originally posted by dhwilkin LOL, oops, guess I should've phrased my last question better. I appreciate the op-amp comparison, Hirsch, but when I said "top amps", I meant the top headphone amplifiers at the meet (RKV, MicroZotl, and Melos). I'm especially curious about the "character" of the RKV, and if a raised noise floor was noticeable w/ any of the low-impedence headphones. BTW, how much difference do you feel changing the power supply made to the DI/O's sound, as opposed to the internal mods?

Whoops. You got me thinking in terms of the DI/O, and I saw op amp.

The power alterations, both external and internal, are probably the most significant modifications to the DI/O.

I'm going to have to beg off on the noise floor question, for the most part. There was too much going on to make very fine judgements. However, the RKV was just fine with the HP-1 and CD-3000, both fairly low impedance headphones. The ZOTL had a lower noise floor IMO (what noise floor?), but the RKV handled the low impedance cans nicely.