[Penchum]

Quote:

Originally Posted by dsmudger /img/forum/go_quote.gif Did some listening yesterday/here's some first impressions.. To be perfectly honest (and this seems to go against what most are saying on here..) I didn't like the stock sound very much at all.. maybe it's that I'm playing into Grados (RS1), unlike I think many on here who have Sennheisers (HD650)? Couldn't help myself and started swapping opamps (sorry penchum, I know you say this isn't recommended but surely I can let it burn in with some better opamps? +does it really make that much of a difference?? ) Tried a bunch of combinations, but haven't found one yet that beats my Headroom Total Bithead (tell the truth, I've found some new respect for it after comparing with the stock Zero and some of the less-good opamp combos..), however LM4562 in the mainboard and LME49720 in the headamp makes it sing quite nicely for my taste and comes pretty close - this amount of difference, I could believe will improve with burn in.... (might leave it like this for a bit now/not sure yet..) Some notes on some of the combos I tried (remember this is without burn in and it's playing into Grado RS1 which are quite bright revealing phones compared to Sennheiser HD600 for example.. though not sure how they might compare to HD650?) (notes kept short, so prob. a bit exagerated/might sound a bit harsh!) Stock amp in headamp, changed main to DY2000: more musical, but still didn't like the sound much... Changed to LT1364 in the headamp stock amp in main: muddy overall, raspy/sandpaper-y highs changed to DY2000 in main: still a bit raspy, but more open and more musical changed to LM4562 in main: "aha! hello, this is a bit better..." better clarity, much better 'pace', still a bit raspy Changed back to stock amp in headamp (keeping LM4562 in the main): still muddy overall but some of the better clarity definitely remained compared to stock, upper mid + v. low bass now very recessed, pace ok - better than stock, but worse than with the LT1364 in the headamp Changed to LME49720 in headamp (still the LM4562 in main): "oh wow, now it sings nice!" Bithead prob. still sounds a little better, but I'm listening through entire tracks now, not skipping around straining to hear differences/things I know should be there/switching between sources all the time. Oh, at some point in the proceedings I tried LT1028 in the headamp - they didn't work; just got really hot and the sound came out of only the right channel at low volume, + turning the volume control knob had no effect on the volume level even down at zero! Was a bit worried, but swapping to something else sorted the problem.. (they were the right way round and pretty sure they were seated in the socket ok..). Sure I was being a complete idiot in one way or another doing that - does anyone know what the actual issue was there? From the rest of the thread, have I inferred correctly that you can put a dual in a single socket and it'll work as a single? (or was that the problem?) Might try swapping the mainboard amp around a bit tonight, maybe see how I get on with the DY2000 as comparing back to back with the Bithead it's this/'musical' quality that's what's slightly lacking with my current amp combo, though they're now on par in terms of pace and detail... (By the way/for reference, I was using just about the most challenging music I have - it's banging hard house, but different to the usual/what you might expect, in that the guys who made it use a lot of real/live instruments (full drum kit/trombone/electric guitars) and they're classically trained musicians so you get an awful lot of nuance/subtlety/structure in there.. (not just fast synths over the top of BANG BANG BANG BANG ). I've listened to it a lot/know the material well, so I hear immediately if something's missing and it's also a great test of this 'pace' thing I keep referring to... anyway, thought I should mention as I'm sure the type of music makes a difference with this sort of thing.../i.e. some of the combos I listed as didn't-like-it might well be awesome for less detail+pace-orientated music..)

Yes, this is how I imagined the Zero would sound out of the box with bright headphones. Maybe you see now, a little, that early swapping means you'll be back swapping again, later. NO biggie! The LT1028 is a single, not a dual, so ya, it will not work without two on an adapter. There is no room on the headphone board for the adapters, so we are limited to Dual Opamps only.

Good luck!!

 

[Penchum]

Quote:

Originally Posted by mapstec /img/forum/go_quote.gif Well, the LT1028 is a single opamp and so you need the two you have on an adapter to replace any one of the opamps used in the zero. So you would need 4 and two adapters for the headphone amp. On a different note, I just switched the Zero to pure DAC duty and right now I am seriously underwhelmed!! Strange .... Please bear in mind, unit is just two hours running... I will investigate further and keep you posted.

Do you have the stock Opamps in it still, or did I miss a post. Eh, what a day for me! I'm so glad you guys got your units! Time is on your side now, let them babies burn-in before too much critical listening!

 

[dsmudger]

Quote:

Originally Posted by mapstec /img/forum/go_quote.gif So I got mine today and it is running for something like 30 mins now. The one thin I find interesting is that I can not remember anyone else mentioning that it stinks! I know the odor will dissipate hopefully soon, but still,

You're right - mine smelled of solder flux out of the box (gone now, but I've had the lid off for a while..), I thought of it as/reminded me of new-car-smell, or maybe what one of my friends has termed "the-smell-of-new" - that one you get flicking through a new book or unpacking a new monitor

in other words not entirely unpleasant to some..

 

[fault151]

Quote:

Originally Posted by dsmudger /img/forum/go_quote.gif You're right - mine smelled of solder flux out of the box (gone now, but I've had the lid off for a while..), I thought of it as/reminded me of new-car-smell, or maybe what one of my friends has termed "the-smell-of-new" - that one you get flicking through a new book or unpacking a new monitor in other words not entirely unpleasant to some..

Mine was like that a little bit, it soon went. Wasn't a nice smell was it!

 

[Penchum]

Quote:

Originally Posted by dsmudger /img/forum/go_quote.gif You're right - mine smelled of solder flux out of the box (gone now, but I've had the lid off for a while..), I thought of it as/reminded me of new-car-smell, or maybe what one of my friends has termed "the-smell-of-new" - that one you get flicking through a new book or unpacking a new monitor in other words not entirely unpleasant to some..

There is your million dollar idea! Home spray freshner that smells like new electronics! Every audiophile would have to buy some!!!

 

[dsmudger]

Quote:

Originally Posted by Penchum /img/forum/go_quote.gif The LT1028 is a single, not a dual, so ya, it will not work without two on an adapter. There is no room on the headphone board for the adapters, so we are limited to Dual Opamps only. Good luck!!

Right ok thanks for straightening that one out

My reasoning went that since there appeared to be two ICs (on a symmetrical looking board as well..) they must be singles, one for each channel

(so if I'm right in thinking single=single channel/mono, dual=dual channel/stereo - do they use two duals so they can link the two channels of each so they can get higher gain out of fewer components/smaller PCB?)

EDIT: Hang on, I just realised/don't think you can chain amps of equal specification running off the same voltage rail like that and get any extra gain.. obviously got the wrong end of the stick - why do they use two duals in the headphone board?

 

[fault151]

Quote:

Originally Posted by dsmudger /img/forum/go_quote.gif Right ok thanks for straightening that one out My reasoning went that since there appeared to be two ICs (on a symmetrical looking board as well..) they must be singles, one for each channel (so if I'm right in thinking single=single channel/mono, dual=dual channel/stereo - do they use two duals so they can link the two channels of each so they can get higher gain out of fewer components/smaller PCB?) EDIT: Hang on, I just realised/don't think you can chain amps of equal specification running off the same voltage rail like that and get any extra gain.. obviously got the wrong end of the stick - why do they use two duals in the headphone board?

I wonder what Lawrence was on about then, he said to put the two opa 627's on browndogs in the headphone amp. Unless he was going to force them in to fit. I can't see ho w though. Theres two little resistors in the way which would need bending down.

 

[Penchum]

Quote:

Originally Posted by dsmudger /img/forum/go_quote.gif Right ok thanks for straightening that one out My reasoning went that since there appeared to be two ICs (on a symmetrical looking board as well..) they must be singles, one for each channel (so if I'm right in thinking single=single channel/mono, dual=dual channel/stereo - do they use two duals so they can link the two channels of each so they can get higher gain out of fewer components/smaller PCB?) EDIT: Hang on, I just realised/don't think you can chain amps of equal specification running off the same voltage rail like that and get any extra gain.. obviously got the wrong end of the stick - why do they use two duals in the headphone board?

Quote:

Originally Posted by fault151 /img/forum/go_quote.gif I wonder what Lawrence was on about then, he said to put the two opa 627's on browndogs in the headphone amp. Unless he was going to force them in to fit. I can't see ho w though. Theres two little resistors in the way which would need bending down.

I'm pretty sure that Shopper asked him that question somewhere, but the answer was one (dual) Opamp for each channel, L&R. I had ASSumed it was for the extra gain, allowing larger loads like 600ohm loads? But, I've slept since then, so I could be totally wrong.

 

[charley phogg]

Quote:

Originally Posted by fault151 /img/forum/go_quote.gif Cheers, im letting the zero dac and head amp burn in then i'll begin comparing the two. I may change the op amps in my zero first though. So far i really like the zero.

Good to hear you like it. I've been following this thread from the beginning as it's one of the dac's I'll be considering for my next upgrade after my Green comes. Going to be a bit before I can do that though, and I'm unsure if I'll go this route, or hold off and just go direct to a higher end dac. But I do like hearing the improvements as I move up the food chain and think it will be fun in modding and rolling opamps. Guess it really depends how soon upgradietis sets in after my new baby comes.

 

[Penchum]

Quote:

Originally Posted by charley phogg /img/forum/go_quote.gif Good to hear you like it. I've been following this thread from the beginning as it's one of the dac's I'll be considering for my next upgrade after my Green comes. Going to be a bit before I can do that though, and I'm unsure if I'll go this route, or hold off and just go direct to a higher end dac. But I do like hearing the improvements as I move up the food chain and think it will be fun in modding and rolling opamps. Guess it really depends how soon upgradietis sets in after my new baby comes.

It is actually good you are keeping the Zero in the back of your mind. I don't know about the rest of these fellas, but when my babies arrived, I found myself looking to get satisfaction on a very tight budget. Those little ones sure can burn a budget quick!! Good luck on the little one!!!

 

[mapstec]

Did I mention I am not the patient type?

Swapped the DAC opamp for my personal favorite: OPA2107.

Happy listening now, need to test the DAC out later and then let the Zero simply burn / settle in.

Penchum, you are right, one should always keep the budget in mind.
I am looking for something cheap but good for the work desk and the Zero certainly fits the bill.

 

[mapstec]

Has someone tried to trace the circuitry of the Zero?

When I look at the layout and the fact that you can not listen to the headphone out when the external DAC out is active I thought that one of the relays at the back of the Zero is responsible for routing either to the external out or to the headamp.

Now I wonder about the various wires between the main board and the amp board:

I believe that the three stranded wire is the power supply and that leaves two sets of four that very much look like two stereo connections.

Now one I would understand: from the Dac to the headamp for amplification and then to the headphone socket.

But what about the second pair? Does it go back from the headamp to the main out? I am not good enough to deduce it from the layout.

Anybody any ideas?

I don't want to to try and unclip various wires to see what then does not work anymore....

 

[Penchum]

Quote:

Originally Posted by mapstec /img/forum/go_quote.gif Has someone tried to trace the circuitry of the Zero? When I look at the layout and the fact that you can not listen to the headphone out when the external DAC out is active I thought that one of the relays at the back of the Zero is responsible for routing either to the external out or to the headamp. Now I wonder about the various wires between the main board and the amp board: I believe that the three stranded wire is the power supply and that leaves two sets of four that very much look like two stereo connections. Now one I would understand: from the Dac to the headamp for amplification and then to the headphone socket. But what about the second pair? Does it go back from the headamp to the main out? I am not good enough to deduce it from the layout. Anybody any ideas? I don't want to to try and unclip various wires to see what then does not work anymore....

Not that I'm aware of. I know there are IC controlled switching circuits and also protection circuits for both the DAC and Head board. I've been too busy enjoying it!!

 

[jamato8]

Has anyone tried the LT1364 in the DAC, and two LT1469 in the headphone amp?

 

[Penchum]

Quote:

Originally Posted by jamato8 /img/forum/go_quote.gif Has anyone tried the LT1364 in the DAC, and two LT1469 in the headphone amp?

Not exactly.

I started with the idea of keeping the OPA627s in the DAC, then tried many others and ended up keeping the LT1364s in the head board.

When I get the chance, I'll do some more swapping and see how it sounds.