[karthur]

Quote:

Originally Posted by blue_lammer /img/forum/go_quote.gif Must they put LED's into every electronic component these days?? If I end up putting one of those in my computer I could set up a disco room from the lights. Does anyone know the effects of a HDAM + opamp combination would be. The soundcard im looking at has 3 op-amp slots, 2 are "paired" and the other is alone. Would the benefits of installing a HDAM be removed from the other two opamps? I think the path goes Single Op --> Pair --> RCA

Yeah, just doesn't seem too high-end with the LEDs...the Moon doesn't have any btw.

It depends on what the design is with the opamps..Are you sure the path you outlined is correct? The two that are paired could be used as buffers and the third could be the driver (or whatever you call it in opamp circuit design world) - the one suitable to be changed with the HDAM... so it would be pair buffers -> hdam -> RCA

 

[Ricey20]

I think you perfectly described the Moon vs Sun. Even on Audio-gd's site they said the Moon was supposed to be more similar to a tube while Sun to be more analytical.

 

[blue_lammer]

Quote:

Originally Posted by karthur /img/forum/go_quote.gif Yeah, just doesn't seem too high-end with the LEDs...the Moon doesn't have any btw. It depends on what the design is with the opamps..Are you sure the path you outlined is correct? The two that are paired could be used as buffers and the third could be the driver (or whatever you call it in opamp circuit design world) - the one suitable to be changed with the HDAM... so it would be pair buffers -> hdam -> RCA

Hmmm the stock configuration is 3x NE5532. I guess two of them could be buffers for the sound but I really don't know. I'm not sure if this picture helps either, it's the "upgraded" version.

Well if it does make a difference I'll take one of your HDAMs off of you if you decide to sell

 

[boogiemk4]

Quote:

Originally Posted by lag0a /img/forum/go_quote.gif Has anyone tried comparing the SQ of the opa637sm or any opa637 with the Moon HDAM?

I've swapped out an OPA637BP pair with the Moon HDAM. I bought it used, and it has been broken-in. Just to let you know, I'm also using the X-Meridian card, first with the stock opamps, then the LM4562's, then to the OPA637BP's, then to the Moon HDAM. The move from LM4562 to OPA637BP added more bass punch and high-end clarity. The move from OPA637BP to Moon HDAM added some more bass punch and a lot more bass control! Songs with dry bass lines now sound fuller. I can follow bass lines now when listing to songs, imagining the bassist being sucked into the music while playing his/her bass. The mids, especially with violins, trumpets, and vocals all of a sudden sound pleasant to the ears, with the harshness gone The hi-end of the frequency spectrum also got more smooth and no more harshness.

My wife and I went to an audio store checking out these $15k tower speakers last month. Then she said that those sound smoother and less fatiguing than the system that we have at home. I said, yahh... with $15k speakers and another $15k of electronics, why not. Then I read this post about the Moon HDAM, and decided that a $30 upgrade won't hurt much. Now, my wife said that our $3k or so system with the Moon HDAM sounds much better than the $30k system ($15k + $15k) that we heard last month.

I'm playing FLACs thru foobar with no dsp, going thru the X-Meridian, to its 3.5mm output, to a 28awg 3-ft pure silver cable, to an AKSA kit, and then to a pair of Madisound Cygnet MkII speakers. This is not a headphone setup, but since the question asked for a comparison between the Moon HDAM and the OPA637, so here it is.

My wife has way better ears than mine, and can tell the difference between $600 cables and $400 cables, via a blind test at a hi-end audio store. While I could not tell the difference between those cables, I can tell the difference with the Moon HDAM, and by all means it is not subtle. Instruments are more separated throughout the soundstage, which became much bigger by the way. The Moon HDAM is staying. Bye-bye opamps....

 

[Pricklely Peete]

The leds serve a specific electrical purpose (diode) in the SUN circuit. They aren't there for show only.

Peete.

 

[theBigD]

Quote:

Originally Posted by karthur /img/forum/go_quote.gif Ok so here's a photo of the Sun v2 attached to the X-Meridian. It isn't been burned-in (has something like 10 minutes on it) but I find the sound to be brighter and hollower than the moon with slightly less detail on the low end. In fact, the bass seems muffled compared to the Moon....even though I think the Moon has a warmer sound overall...kinda strange...I don't have enough experience comparing opamps to come up with a better description, but I think I prefer the moon. The Sun v2 sounds great though. I didn't realize the LEDs on it would be green.

Remember that the hdams need lots of burn in to stabilize. In the first 50 hours the midrange on the moon is a bit forward and edgy and warms up and mellows after 50hr. Many say up to 300 hr burn in is necessary for them to fully mature.

Yeah i find the bass on the sun to be much more puncy and dynamic than the smooth but more extended bass of the moon. I seem to prefer the sun.