The Stax thread (New) - Page 1304

Quote:

Originally Posted by PretentiousFood 

Stax newbie here! I just picked up a Lambda Pro Signature with an SRD-7 pro-bias mod transformer box / energizer, and will have it next week. I searched through the thread but it's a bit of a monster at this point. I'm trying to figure out what amp I need to drive these.

 

First, and probably dumbest question: can I drive the transformer box with the speaker taps of my Denon receiver? I know it will sound terrible compared to a proper amp, but I'll definitely want to give these a listen as soon as they get here!

 

Otherwise I'm looking for the best bang-for-buck amp. I'm considering the Passlabs F5 (25W/channel class A) but that seems way overkill. I only need voltage swing, and not power, right? Why couldn't I use something op-amp based like the NwAvGuy O2 headphone amp modded for higher gain? Is there any default recommended pairing for the SRD-7 that I should consider?

Yep, any speaker amp will do.  Connection instructions are on the back of the transformer box.

Quote:

Originally Posted by Keithpgdrb 

I forgot about that.  I'll check that out.

nope.  the offset isnt effected at all by moving the other pot.  Balance is dialed in, but offset, with the pot turned all the way down, wont go past about -14v on the left, and about -16v on the right.

is there I test point I can check?

bad resistor somewhere?

oh, and also, that glue that bound the pots was pretty strong.  I cracked a couple plastic tops, and one piece even broke off.  not as easily broken as I would have hoped.  doesnt seem to effect the pots themselves though.  

Quote:

Originally Posted by Keithpgdrb 

nope.  the offset isnt effected at all by moving the other pot.  Balance is dialed in, but offset, with the pot turned all the way down, wont go past about -14v on the left, and about -16v on the right.

 

is there I test point I can check?

 

bad resistor somewhere?

 

oh, and also, that glue that bound the pots was pretty strong.  I cracked a couple plastic tops, and one piece even broke off.  not as easily broken as I would have hoped.  doesnt seem to effect the pots themselves though.  

ok, wait.. I'm sorry, I lied a little.  I was able to set the offset to 0v using the balance pot, but then then the balance wont go below about 30v on each channel.  so something is off.  in fact, the readings hardly move at all when moving the offset pots to control the balance.

Something is indeed off but I very much doubt the recent parts change had anything to do with it.  Most probable are carbon resistors drifting.  What we can do is increase the size of the pots a bit and see if that gives you some more range to work with.  The values are printed onto the side of the pots.  According to my schematic the balance should be 1k and the offset 200R. 

If changing the pots and leaving the resistors is the way to go, then thats what I'll do.  The great thing about this amp is its really easy to get to everything.

am I going to have to worry about the resistors drifting a lot further over time?

Here's a shot of the offset, and balance pots.  What should I replace them with?  again, it "seems" the balance pots are working correctly?  but should I just do the all?  I suppose if it isnt broke.. etc...

Quote:

Originally Posted by Chodi 

I was just wondering if you get the expected 6db gain with the balanced inputs on this amp?

Yes, I always get some more gain with XLRs, but the amount depends on the amp. The gain is not related to sound quality I find.

this question is probably discussed before but I couldn't find it. How well does stax lambda range especially the 407 respond to eq ? 
I prefer the 1 phone solution so eq is the easiest way to archive it. I'm making decision between he-6 and a ges+ 407 combo. 

check the 33k plate resistors

Quote:

Originally Posted by xzobinx 

this question is probably discussed before but I couldn't find it. How well does stax lambda range especially the 407 respond to eq ? 
I prefer the 1 phone solution so eq is the easiest way to archive it. I'm making decision between he-6 and a ges+ 407 combo. 

I've had the 407 since Sunday. I have it paired with the 006t (came in the 4170 combo). I have little doubt that the ges from Woo would be better. I normally use eq when I play my T1's so naturally I tried it on the new 407. It responds exactly as you would expect it should but I found that on this combo no eq was really needed or desirable. My new Stax system has taken all four days and about 60 hours of burn in to reach much of the potential I think the system is capable of achieving. I can tell you that the 407 is one very remarkable headphone. Don't judge it out of the box as it takes some time to burn in and mine is probably not finished the burn in process yet. Even so, at this point the sound from the 407's does two things better than any headphone I own or that I have heard. They sound the same at any volume level which is entirely unique. No raising the level to catch the detail or get the correct tonality. Secondly, they are fast, very fast and kill even my T1's on transients and attack. There are other positives about the 407 but this is not an attempt at a review. They are extremely well balanced top to bottom so you may find like me that they do not need any eq. I would personally rate these one of the best values out there in headphones. 

Thanks for the input. If I buy from local here the price of the two combo is similar and from my research the woo seems to be the preferable one so  I chose it. May be you're right every one just feels satisfy with the sound and have no use for eq. If I have chance to listen to stax all decision should be much easier. It's easy to audition dynamic here in Melbourne but estat is another matter.

Quote:

Originally Posted by Chodi 

I've had the 407 since Sunday. I have it paired with the 006t (came in the 4170 combo). I have little doubt that the ges from Woo would be better. I normally use eq when I play my T1's so naturally I tried it on the new 407. It responds exactly as you would expect it should but I found that on this combo no eq was really needed or desirable. My new Stax system has taken all four days and about 60 hours of burn in to reach much of the potential I think the system is capable of achieving. I can tell you that the 407 is one very remarkable headphone. Don't judge it out of the box as it takes some time to burn in and mine is probably not finished the burn in process yet. Even so, at this point the sound from the 407's does two things better than any headphone I own or that I have heard. They sound the same at any volume level which is entirely unique. No raising the level to catch the detail or get the correct tonality. Secondly, they are fast, very fast and kill even my T1's on transients and attack. There are other positives about the 407 but this is not an attempt at a review. They are extremely well balanced top to bottom so you may find like me that they do not need any eq. I would personally rate these one of the best values out there in headphones. 

After break-in, the 407/507 will have less attack, but more neutral.

their response is ultra linear & precise

the vintage lambda are musical,but not as precise as the 407/507.

better find some amp than 006t IMHO, at least a srm600, or do some mod to the 006t.

(007t is similar to 006t, just more power)

when they are proper amped,you will get a more liquid & sweet sound

Quote:

Originally Posted by pkshan 

After break-in, the 407/507 will have less attack, but more neutral.

their response is ultra linear & precise

the vintage lambda are musical,but not as precise as the 407/507.

 

better find some amp than 006t IMHO, at least a srm600, or do some mod to the 006t.

(007t is similar to 006t, just more power)

 

when they are proper amped,you will get a more liquid & sweet sound

It is my intention to get a 323S as soon as I can and compare them. Then I will sell whichever one I don't want. The dealer here in Bangkok doesn't stock the 323S so I will have to get it elsewhere. If I see one come up used I will grab it. My voltage is 220v so I will wait for that.

Quote:

Originally Posted by n3rdling 

 

Yep, any speaker amp will do.  Connection instructions are on the back of the transformer box.

Thanks! I hope the receiver isn't too terrible, now I'm excited!

Quote:

Originally Posted by spritzer 

Something is indeed off but I very much doubt the recent parts change had anything to do with it.  Most probable are carbon resistors drifting.  What we can do is increase the size of the pots a bit and see if that gives you some more range to work with.  The values are printed onto the side of the pots.  According to my schematic the balance should be 1k and the offset 200R. 

I dont see 1k or 200R anywhere?  

Offset - B50XΩ J  Board lists them as 50k

Balance - B5KΩ M  Board lists at 5k

I wonder if I could pick these up at a place like radio shack?  or are they just too cheap?  Would this work for the offset?  http://www.radioshack.com/product/index.jsp?productId=2062302&filterName=Type&filterValue=Trimmers

again, I can instal it, but I'm not educated enough to pick the proper parts yet.

should I just replace the offset pots?  or should I do both sets? 

Quote:

Originally Posted by PretentiousFood 

 

 

Thanks! I hope the receiver isn't too terrible, now I'm excited!

 

I tried an SRD-7 pro / SR-007 and Lambda Pro Signature 'phones on a number of different amplifiers- Monarchy zero-feedback class- A, class A hybrid MOSFET-EL34, 845 Single Ended Triode, H-K Citation II, First Watt F3 clone, as well as an NAD 7255 receiver and old Yamaha integrated amp.  The differences between these amps on the SRD-7 were not huge, except the F3 clone had a rolled off high end and with the 845 SET amp I heard some hum.  The Yamaha integrated amp (model A-700) had a little bit of a  harsh quality in the treble- some harshness but not overwhelmingly so.

It seemed that the SRD-7 did not require very much power at all-  even the 15 watt F3 was capable of producing any volume I wanted.

The better amps did sound a LITTLE better, but the old NAD and Yamaha were quite acceptable.  I think you'll find your receiver is just fine.

I do have to say that the direct-drive Stax amps I used ( SRM-1 mk II and SRM-T1) do sound better, they offer more transparency and more refinement in the sound, but this was not to say that they were WAY better than the SRD-7.  They were better, yes, but not overwhelmingly so.