[Hansotek]

Hey gents, I have a thought for all of you and would like to have some feedback from those who have very hot sources and need attenuation.

I know that some of you are using some kind of passive attenuation. In general, pure passive attenuation can affect the SQ because of the resistance introduced into the input stream turning the source from low impedance output to high(er) impedance output.

There is another way though. It would be a simple matter to create an active attenuator using high quality audio opamps. Attenuation would be done with a simple voltage divider before the opamp inputs. The easiest way to power such a thing would be two 9V batteries.

The advantage of this is that the source would still see a high impedance load, but the amp would see a low impedance source at the outputs of the opamps.

Batteries would ensure no significant noise introduction at the input to the amp beyond the inherent component noise.

I don't think the opamps (chosen properly) would have any audible effect on the SQ because the opamps would be operating in a very lightly loaded situation which would not incur significant THD, etc.

So just an interest check. Anyone interested in this? And if so...

1. Is my proposed method of powering ok?
2. What gain reduction would you want? Cut it by 1/2 (6db). Less? More?

I don't think something like this is needed for most situations, but there do seem to be some where it might be helpful.

Perhaps a switch for -6db and -12db. IMO, anything under 6db will be useless. -12db might add some versatility for extra sensitive headphones like the Cascade or Fostex TH models, which both match SUPER synergistically with the LP.

 

[Rattle]

Hey gents, I have a thought for all of you and would like to have some feedback from those who have very hot sources and need attenuation.

I know that some of you are using some kind of passive attenuation. In general, pure passive attenuation can affect the SQ because of the resistance introduced into the input stream turning the source from low impedance output to high(er) impedance output.

There is another way though. It would be a simple matter to create an active attenuator using high quality audio opamps. Attenuation would be done with a simple voltage divider before the opamp inputs. The easiest way to power such a thing would be two 9V batteries.

The advantage of this is that the source would still see a high impedance load, but the amp would see a low impedance source at the outputs of the opamps.

Batteries would ensure no significant noise introduction at the input to the amp beyond the inherent component noise.

I don't think the opamps (chosen properly) would have any audible effect on the SQ because the opamps would be operating in a very lightly loaded situation which would not incur significant THD, etc.

So just an interest check. Anyone interested in this? And if so...

1. Is my proposed method of powering ok?
2. What gain reduction would you want? Cut it by 1/2 (6db). Less? More?

I don't think something like this is needed for most situations, but there do seem to be some where it might be helpful.

I thought the spark had perfect gain 3db/6db however I only plugged 300ohm senns into it.
LCD-2C might require 4.5/9 ... If things are more senstitive than that we shouldn't be plugging them into an amp like the LP ... You can't make everyone happy I guess.

 

[kumar402]

In my experience, the Sys seriously degrades sound quality.

Oh no I just got one delivered today. Yet to set it up

 

[Hansotek]

Oh no I just got one delivered today. Yet to set it up

Your findings might not align with my own. Good luck.

 

[Hansotek]

I thought the spark had perfect gain 3db/6db however I only plugged 300ohm senns into it.
LCD-2C might require 4.5/9 ... If things are more senstitive than that we shouldn't be plugging them into an amp like the LP ... You can't make everyone happy I guess.

While I agree with your point that the Spark has a perfect volume curve, I disagree with your point on the LP. The LP’s background is quiet enough to allow an extremely wide range of gear. This notion you are floating is totally false. Sensitive gear can benefit greatly from enormous power reserves, just try any of the Fostex/Emu dynamics.

 

[funch]

I just tried turning the amps volume all the way up, and using the volume on the attenuator box I built (post #1221), and notice a big improvement. Extended highs, bigger soundstage, more open sound.
It really has shown me the limitations of the stock, smaller pot. The pot I used in my box is a 50K Alps.
This one to be exact: https://www.ebay.com/itm/1PCS-ALPS-...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2648

 

[Rattle]

While I agree with your point that the Spark has a perfect volume curve, I disagree with your point on the LP. The LP’s background is quiet enough to allow an extremely wide range of gear. This notion you are floating is totally false. Sensitive gear can benefit greatly from enormous power reserves, just try any of the Fostex/Emu dynamics.

I get where you're coming from, like I said I don't have any experience with gear that sensitive. The LP is the highest end amp I've owned. I was just thinking out loud trying to make the point where noise comes into play and also volume pot issues with higher sensitivity gear. That's good to know that the LP is that clean that it isn't a concern.

 

[MikeW]

In my experience, the Sys seriously degrades sound quality.

interesting, that's the first i've heard of it. Wonder what a better alternative is. Windows mixer software attenuation is no bueno either. Active pre-amps are expensive. Maybe the JDS labs switch/pre

Edit: hard to find any negative comments on sys, even amir likes it, and he does not like any schiit products lol. Given the way the device works however, it may be more or less harmful depending on what it's connected to, and how sensitive that device is to impedance.

 

[betula]

Can someone please post a pic of the power supply? I have ordered the LP from the US and while I am waiting for its arrival I'd like to sort out my power cable.
Can I buy something like this, or the only way is a plug adapter? I can't find description or close up pic of the LP's ps online.

 

[rockytopwiz]

https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.com/ulk/itm/253180664213

I'd say itll prolly add coloration, but 35 skins and balanced.

 

[Thenewbie76]

Since this is a tube amp it's not recommended I use it with IEMs and planar right? Only dynamic headphones. I have the hd 600 and ZMF aeolus which I plan to use. Would it be a good match up ?

 

[skyline315]

Since this is a tube amp it's not recommended I use it with IEMs and planar right? Only dynamic headphones. I have the hd 600 and ZMF aeolus which I plan to use. Would it be a good match up ?

No. Tube Hybrids like the LP are great for planars.

This is different from a full tube design.

 

[Thenewbie76]

@skyline315 oh ok .But if it's a hybrid would it still have that 'tube signature ? Is there any benefits between a full tube design and a hybrid ? Can I use a hybrid for IEMs?

 

[Schwibbles]

Since this is a tube amp it's not recommended I use it with IEMs and planar right? Only dynamic headphones. I have the hd 600 and ZMF aeolus which I plan to use. Would it be a good match up ?

It sounds like you're thinking of an OTL tube amp in which you're right.

In the case of the LP, it is a hybrid amp meaning that it uses solid state amplification in conjunction with a tube. Generally, the tube in a hybrid amp is there for some sound coloration while most of the grunt work is handled by the solid state section. The LP is fantastic with planars and IEMs (granted you use a preamp to lower the volume); it can drive pretty much anything.

EDIT: I can confirm the HD600 pairs very nicely with the LP.

 

[Thenewbie76]

It sounds like you're thinking of an OTL tube amp in which you're right.

In the case of the LP, it is a hybrid amp meaning that it uses solid state amplification in conjunction with a tube. Generally, the tube in a hybrid amp is there for some sound coloration while most of the grunt work is handled by the solid state section. The LP is fantastic with planars and IEMs (granted you use a preamp to lower the volume); it can drive pretty much anything.

EDIT: I can confirm the HD600 pairs very nicely with the LP.

I have no idea what OTL means but it sounds like a hybrid is better. Since it still offers that tube coloration to the sound. Any ideas why people won't go for hybrids and why OTL tube amps are still being made?