[WilliamLeonhart]

BTW is anyone using the Voshkod 6ZH1P-EV made in "07-81"? Mine have somewhat dry mids, fuller bass and non-exceptional trebles... Overally quite boring.

 

[MunkyOne]

  With others saying there are fake muses 02 out there, would anyone know if this is legit?
 
http://www.amazon.com/gp/product/B00B086ZTQ?colid=2ZO3U2NKSKWCV&coliid=I34INO5GJERP9&ref_=wl_it_dp_o_pC_S_ttl

There may well be fake op-amps out there; especially the more expensive ones.   Best to purchase from specialist electronic suppliers to avoid the risk.   I purchased mine from Mouser, but they are available from Farnell, Digikey etc. also.  Companies like these, source components direct from the manufacturer or main distributor.
 
Amazon is no safer than ebay for electronic components.

 

[MunkyOne]

  Does the fact that the I+ is a hybrid have anything to do with the need/un-need for matched pair?

No.  It does not matter the architecture of the circuit.  In all tube amps, the choice of matched vs unmatched is always a matter of preference.  Some will swear they hear a difference, wile some will swear otherwise.   Noticeable differences are more likely if the tubes were manufactured in a different company, location or year, as the manufacturing processes are always evolving.
 
It is worth noting, that in the LD1+, it makes even less of a difference than a pure tube amp. The tubes are providing some current gain into the inverting input of the op-amp, and with it some nice tubey flavour.
 
Try some of the less expensive ones, matched and unmatched, and see if you can tell.  As with everything hi-fi, it is always subjective.

 

[Rossy007]

Just popped in a muse02 and was quite surprised at the difference. Vocals are a bit hard but I am hoping that will change (don't know if op-amps need burning in). definitely more detail and the bass is superb, makes my Q701's sound warm and deep. I feel like the soundstage has narrowed a bit but its early days yet.
 
Thanks everyone who have recommended this amp.

 

[iamxLn]

what did you come from? 

 

[Rossy007]

A2107, and the muse02 seems louder. I now have the volume at about 3 whereas before it was 4-5. don't know if that's making a difference?

 

[MunkyOne]

  Just popped in a muse02 and was quite surprised at the difference. Vocals are a bit hard but I am hoping that will change (don't know if op-amps need burning in). definitely more detail and the bass is superb, makes my Q701's sound warm and deep. I feel like the soundstage has narrowed a bit but its early days yet.
 
Thanks everyone who have recommended this amp.

Unlike tubes and other discrete components, there's so little physical material in op-amps that burn-in is not really a factor.   What tubes are you currently listening with?  Currently, I am listening with the MUSES02 op-amp and 6ZH1P-EV tubes.  No hardness of vocals, Wonderfully open and clear, with deep yet very well controlled bass.   With Grado 325e and AKG K550.   Having said that, I have made some cicuit mods to the amp, which have improved it's sound.

 

[Michael V]

 
Unlike tubes and other discrete components, there's so little physical material in op-amps that burn-in is not really a factor.   What tubes are you currently listening with?  Currently, I am listening with the MUSES02 op-amp and 6ZH1P-EV tubes.  No hardness of vocals, Wonderfully open and clear, with deep yet very well controlled bass.   With Grado 325e and AKG K550.   Having said that, I have made some cicuit mods to the amp, which have improved it's sound.

What mods have you done?

 

[MunkyOne]

  What mods have you done?

Vbe mod: connected a 0.1uF cap between the bases of each output transistor pair, to bypass the Vbe multipliers.  This removed the transient at around 10KHz, so treble a bit smoother, especially at higher volumes.
 
Upgraded all main caps to higher quality versions, but kept the values the same.  This can be a pain due to limited space in the chassis. 
 
Volume pot upgraded to higher quality ALPS version.  Same 100K ohms.
 
Generally just trying to make the most of the existing circuit design, which apart from a couple of things is very good.   For some reason they chose to connect the tubes output to the inverting input of the op-amp, which results in phase inversion.  This is something I may experiment with at a later date, but for now, I am enjoying the LD1+ as it is.

 

[MunkyOne]

Michael V:
 
How did you get the Burson op-amp into the LD case?    I have used some of these in my home made DACs and they are quite tall.  Sound good though.
 
How is the sound with the Burson op-amp and the 6ZH1P-EV tubes?

 

[Michael V]

  Michael V:
 
How did you get the Burson op-amp into the LD case?    I have used some of these in my home made DACs and they are quite tall.  Sound good though.
 
How is the sound with the Burson op-amp and the 6ZH1P-EV tubes?

I'm going to order an extender for it, I just have the amp on it's side right now with the bottom open.
 
Can't say I hear a difference at all. I still can't discern any audible differences between my iphone 6s+ and my computer with an asus xonar stx soundcard and the ld1+

 

[peter123]

A while ago I decided to dedicate and tune my LD I+ for the Fidelio X2's and after trying a lot of different configurations I've now settled on Siemens 6AK5W tubes paired with MUSES8820 op amp. Sounds seriously good and the best I've ever heard the X2's to my ears.
 
I'd really like to try the Burson SS V5 op amp in my LD but I'm afraid it's going to sound too good and since it doesn't fit with the lid on it would be terrible to know that it can sound even better than it does now but not being able to take advatage of it 

 

[Michael V]

  A while ago I decided to dedicate and tune my LD I+ for the Fidelio X2's and after trying a lot of different configurations I've now settled on Siemens 6AK5W tubes paired with MUSES8820 op amp. Sounds seriously good and the best I've ever heard the X2's to my ears.
 
I'd really like to try the Burson SS V5 op amp in my LD but I'm afraid it's going to sound too good and since it doesn't fit with the lid on it would be terrible to know that it can sound even better than it does now but not being able to take advatage of it 

Burson sells an extender for it so you can put it anywhere you want and it will fit in the 1+ that way

 

[nahpungnome]

 
Vbe mod: connected a 0.1uF cap between the bases of each output transistor pair, to bypass the Vbe multipliers.  This removed the transient at around 10KHz, so treble a bit smoother, especially at higher volumes.
 
Upgraded all main caps to higher quality versions, but kept the values the same.  This can be a pain due to limited space in the chassis. 
 
Volume pot upgraded to higher quality ALPS version.  Same 100K ohms.
 
Generally just trying to make the most of the existing circuit design, which apart from a couple of things is very good.   For some reason they chose to connect the tubes output to the inverting input of the op-amp, which results in phase inversion.  This is something I may experiment with at a later date, but for now, I am enjoying the LD1+ as it is.

Sounds like fun, I wish I knew how to do all that  I read on one of the reviews here that changing the potentiometer made a huge difference in sound and they also used an ALPS version.  You'd have to de-solder and solder the ALPS one on yes?

 

[peter123]

Burson sells an extender for it so you can put it anywhere you want and it will fit in the 1+ that way

Aha, I wasn't aware of that. Thanks a lot for this information!