LT1364 + LT1361 opamps, anyone got them?

[krisno]

hi

I tried ordering from Farnell but they only ship to enterprises.

Anyone here have 2x Linear Tech 1364 and 1 x LT 1361 for sale?

Kris

[Deleted]

They do ship to privat persons but you will have to call them and pay upfront (at least in The Neverlands) or fill in some special form.

I've used the LT1361 and it's a nasty IC that oscilates easily when your layout isn't up to spec.
Wouldn't use it for audio.

[krisno]

right...... but its supposed to be good for Audiotrak soundcard.

Can you really hear the oscilliation? how do you nokw it oscilliates?

[Deleted]

You can safely assume Audiotrak used a good board layout (multilayer with groundplanes) and took proper measures and know how to apply this IC.
Not an IC for 'swapping' if you don't have an osciloscope that can do 100MHz or higher or have no experience in designing boards with these high speed opamps.
I've used these in specific purpose Fibre optic transceivers.

You cannot hear oscilations but this can give side effects which can be quite audible but doesn't have to be.
It can upset the power supply of the circuit you use it in.
Interfere with other equipment/IC's and DAC's... too much too mention,
a slight hum might be a dead give-away too (if not caused by a crappy power supply)

I might possibly have some still lying around somewhere.
But you can't say I didn't warn you about these IC's.
You could brush my expertise aside of course and simply do what you set out to do.

[Deleted]

You cannot hear oscilations but this can give side effects which can be quite audible but don't have to be.

Occasionally , this will translate to a marked "graininess"to the sound.
Alex

[oohms]

If it is the audiotrak prodigy HD2, they seem fairly stable with a lot of high speed opamps. (This is only by checking sound, how hot the opamp is etc, not under a scope)
Bypassing the first stage opamps and fitting LM6172 in the last one sounds the best to me (opamp wise), and the opamp does not get warm at all.
I ended up having a single BJT buffer (instead of opamps) for each channel from the noninverting outputs of the dac, since the AK4396 has much less HF noise than most OS dacs. Sounds excellent.

[krisno]

LT1364 and LT1361 is recommended by many HD2 owners........ HD2 stock does not sound good really. It is bright. It is harsh..... big differencefrom Xonar D1... but it sounds more alive. I havp roblem in games, even in Win7 which does all audio in software. there is no 3d positioning at all.

If doesnt work I buy Xonar ST. I just dont want to give up on it totally after I bought it. Its been a box since really.

K

[oohms]

If you have some soldering skills don't give up so easily.. this card with the right mods sounds better than any other i've heard, and being a vout dac with minimal noise, gives much more flexibility in the output stage vs. the xonar STX

I should post more details of what ive done, once i get around to taking out the card from my pc

[krisno]

I dont want to solder too much..... and also the drivers are insainly crappy. So I think I will go for a USB async streamer II+ in the end. But I will try to use the Aduiotrack som more. I never heard the STX..... What opamps you use oohms?

[oohms]

I bypass the first 2 opamps (link pin 1-3 and 5-7 for each one) and use LM6172 in the final stage - this is the best sounding opamp combo i've found so far

I tried LT1364 in the final stage but didn't like the treble so much
OPA2134 was a bit sibilant
THS4032 was very 'dark' - strange phenomenom, but otherwise sounded pretty smooth

Stock NE5532 sounds lively - almost like a grado kind of sound but more subtle - lacks some finer details tho

[Deleted]

I have 4 pieces of LT1361 lying around.

[krisno]

Farnell has delivered it...... I got this local enterprise. But OOHMS.... when you bypass the first 2 opamps, do you get lower volume, or does it stay the same? Does the Headphone out on the card still work or only line-out?

K

[oohms]

Headphone out still works, and volume is about the same

[krisno]

Have you tried the 2x LT1364 1 x LT1361 ?

It sounds nice to have 2 opamps less in the circuit....... how does your "mod" sound? I think the HD2 advance is a little bright and not very musical. But I never really tried to burn it in. I will try that with the new opamps. The HD2 was really dissapointing at start, even vs Xonar D1. Also that the soundcard gives mono sound in games...

[oohms]

I haven't, but i'm guessing that it would sound like a more exaggerated verison of 1x LT1364

The trouble with reading opamp threads is that it is very subjective to personal taste. Some opamp combos I can not stand, while other people love them, and sometimes even the sound signature description i don't agree with at all. (This goes for all opamp rolling threads in general)
Your ears are the best judge imo

[krisno]

I will try your idea as a last resort if this also fails.

Its just that the card STOCK is very bright, and i tried with ADA797 also, but it was bright too. They said on forum that LT1364 + 61 is warm and wide. I feel the card has potential, hardware vice... though drivers suck.

[PinkFloyd]

Kris,

You SERIOUSLY need to get out more and listen to some "real" music. You are not happy with "any" part of your equipment and you keep asking the same question, over and over again and ignore the answers..... you are torturing yourself unnecessarily and you are torturing those around you with your incessant "questions with predetermined answers"......

I'm off to bed for the winter.

Mike.

[oohms]

Bypass the 2 opamps, and keep buying opamps for the final stage, thats what i suggest, since they are cheap. Just make sure they are unity gain stable as well.

This way, you'll slowly build up a collection of opamps to use for other audio gear too

[krisno]

I am sorry you feel that way Mike(really). I dont think there is any reason for this anger towards me right now.

anyways Oohms..... the Audiotrak sounds really good now with the LT1364 and 1361. Its "magical" and musical. But I am using some sennheiser PC160 or something, so I cant really test the card properly. But its alot better. I will try to burn it in for a week and we will see.

K

[Deleted]

I am sorry you feel that way Mike(really). I dont think there is any reason for this anger towards me right now

Kris, just to try and help. Mike is frustrated at your revolving around the same issues and that's the reason for his anger; especially following last time the Valves/V2/V1/V3 issues came up.

I'm not sure that you understand his frustration. That's why your V1 questions probably ended up not being answered this time around.

You're not taking advice but countering any help given and that's precisely what gets peoples' backs up.

It may just be a language thing.

[krisno]

I dont think you guys in general are fair to me.

But I like Mikes products so never mind me going forward

Btw, this audiotrak with the new opamps is really fantastic(on this sennheiser headset). This trumpet solo. Its just so nice. I think Audiotrak, music wise is the best soundcard for the PC. Too bad the drivers are really lacking, especially for games and no MIC in.

K

[krisno]

my god..... it is fcking fantastic, this DAC. and so cheap. But the LT1361s comes with a price. Kind of like listening to end of a tube. Small SS.

[krisno]

I have let the DAC loop 48hours or more with whitenoise. I notice really no difference in SQ I think. But I am using a lowgrade headphone.

[krisno]

Anyone has a LM6172 opamp they can send / sell me? I dont want to use Farnell for that opamp alone. But its important it is not a fake

Oohm, those opamp configurations you listed on this card which you tried, where they all done with bypass in I/V stage and just single opamp in the buffer. Did you try 2x singel channel opamp in the last stage alone? Like ad797?

K

[oohms]

Nov 4, 2010 8:15:29 GMT @krisno said:

Anyone has a LM6172 opamp they can send / sell me? I dont want to use Farnell for that opamp alone. But its important it is not a fake

I use ebay.. sometimes there are fakes but opamps are so cheap

Nov 4, 2010 8:15:29 GMT @krisno said:

Oohm, those opamp configurations you listed on this card which you tried, where they all done with bypass in I/V stage and just single opamp in the buffer. Did you try 2x singel channel opamp in the last stage alone? Like ad797?

K

There is no I/V stage for this sound card.. the opamps that i bypass are just a lowpass filter, which isn't really needed

Straight wires 'sound' much better than having an opamp there, as they would only colour the sound

Keep buying opamps off ebay or something... and maybe upgrade your headphones/amp too, as they are the bottleneck in this setup