[geetarman49]

 
wrt tp21, tp30, and tp41 all have their own separate hp opamp circuitry which mutes spkr outputs from the t-chip.
 
tp21 pix here:  
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=310-310
tp41 here:
http://www.parts-express.com/pe/showdetl.cfm?Partnumber=310-324
 
iirc, the trs jack cannot be directly powered by the t-chip due to common 'gnd' configuration; spkr outputs of the t-amp can be used to drive headphones - left output to left cup, right output to right cup and not via trs connection.
 
some say the hp output from the topping is just avg.
 
<edit 1: most earlier gen. t-amps should be avoided due to lack of turn-on/turn-off transient protection... i.e. very nasty thumps unless you add your own relay cct
edit 2: first gen t-amps also had very poor low-freq response.>
 
hth,

Quote:

Those Toppings are speaker amps with headphone jacks on the front, right?  Don't really need the speaker amps.  Are the headphone jacks run by the class d amps inside?  And any idea of the output impedance on these jacks?  You're right, though, I forgot that the class d stuff is regarded as bright and lean but in a good way.

Quote:

I've tried a few amps with lots of power and i can tell you t50rp does take benefit from this kind of amp so IMO try to consider t amp if you can afford it. I personally haven't heard topping amp so i cann't tell how does it sound. I've no idea about the rest of your question.


 

 

 

[mrspeakers]

Quote:

 
[size=10pt][size=10pt]My understanding is low impedance cans need more current while high impedance ones need more voltage. Maybe that's wrong. Maybe it’s the phase thing in the impedance plot that dictates that. More's not bad, though, regardless. I'm just looking for some good quality amps that are fast and near-zero ohm output. All my headphones are 100ohm or less. [/size][/size]
[size=10pt][size=10pt]I'd prefer something with a built in DAC as my Compaq CQ56, though it does have an o.k. jack on it and I've got an equally competent Syba USB thing that sounds different but good with the Fostex, I'd like some D/A conversion with more pedigree. I have no idea how the laptop's DAC or the Syba measure since I don't have any quality input capability to test them with Rightmark. Some other source of known performance would probably be a better option.[/size][/size]
[size=10pt][size=10pt]Anyone else notice that ambience and low-level detail retrieval seems to improve with burn in on the Fostex driver? It previously did not startle me with extreme side imaging that seemed to come from far off. After playing a lot of pink noise (I don't have the XLO disk with me) for a few nights, it's been kind of freaking me out. Maybe I'm doing something different or it's just placebo effect. But getting startled increasingly from them does seem pseudo-empirical. That wasn't happening before, and it even had a lot missing at first. As I'd said, it was hard to explain what it still lacked even after eqing. This change could certainly be my brain “adapting” to the sound that Tyll talks about, but I haven’t been listening to it much in the past few days as it was running the pink noise.[/size][/size]

You are correct on current vs. voltage.  The other consideration is efficiency, which determines how much power is needed to damage your hearing.  

 
People constantly assume high impedance cans need a lot of power, they don't unless they are low efficiency.  
 

 

[200poundsofamp]

Probably isn't news to anyone, but felt over the white fabric on the driver doesn't do anything if the enclosures well dampened. I think on the Faust mod it helps because it limits the air flow to the driver (same as tuning the vents) and soaks up a lot of the sound that would echo around the inside of the enclosure, but when it's fully dampened it just makes them sound boxed in.

Now I just have to work up the guts to get rid of the white fabric and make these into full blown rastapants...

 

[joelpearce]

Quote:

Now I just have to work up the guts to get rid of the white fabric and make these into full blown rastapants...

I still flip-flop between being glad I did, and kind of wishing I hadn't.  Overall, I like the sound better, but there's something a little funky that I can't quite overcome with any other damping scheme.

 

[sharkz]

Alright, after receiving some Paxmate from a kind fellow Head-fier, I damped the rear of my cups with several pieces. This took away my wonky sibilance and really did seem to open everything up. I am very happy with how these sound now, but I am going to play around with tuning the vents some more (I have them totally closed now). It seems like the combination of mods I have (stiff felt over the outside of the driver, white covering removed from driver, driver covered in softer felt, plastacine covering the baffle, plastacine with Paxmate over it in the cup) is really working. These are still different from my Grados, but are now very enjoyable to listen to now that they have opened up some and have good, strong bass. I do want to see what playing with the vents does. If I can open these up a bit while adding a tiny bit more controlled bass, I would be very happy!

 

[KneelJung]

Quote:

Quote:

Now I just have to work up the guts to get rid of the white fabric and make these into full blown rastapants...

 
I still flip-flop between being glad I did, and kind of wishing I hadn't.  Overall, I like the sound better, but there's something a little funky that I can't quite overcome with any other damping scheme.

I had some corduroy type material covering the driver which I just removed and replaced with what looks like tweed. I put a little strip over two of the vent holes as well. Anyway while I was switching out the cloth on the driver, I inadvertently poked a little corner out of one of the squares. I briefly considered just removing the whole thing but decided not too. the small hole doesnt seem to be effecting the sound, and the tweed (I think that's what it is) has made the phones feel less congested.

 

[sharkz]

Question for everyone here, what do people think of the Little Dot 1+ with these Fostexes? I am currently using an Indeed Mk2 hybrid tube amp, which has decently synergy with the Fostexes and my Grados. I really need to upgrade though as the volume pot on the Indeed is so scratchy I can barely change the volume within certain large blocks without buzzing in one or both channels.
 
I have been looking at Little Dots for a while because they seem nice for the price. The other suggestion I constantly see thrown around is a CTH, although those seem much harder to find....

 

[geetarman49]

i have not tried the LD, but these small hybrids (indeed/bravo/miridiy) are good for the $, but deeply flawed, especially the 1st gen. the indeed g2 (now replaced by g3) is considerably better, but as much as i enjoyed mine, it still has weaknesses.  some of these weaknesses can be fixed by modding/upgrading. 
 
unless you diy, the cth is, as you say, difficult to find.  i would recommend trying garage1217's project sunrise - i have a pre-production unit and it is significantly better than any indeed/bravo (g3 not tested) - modded or not.  it is my current go-to amp for all my phones.  if you go this route (hybrid), tube-rolling opens up the door for improved performance.
 
<edit: if you're handy at diy, you might want to try garage1217's upgrade kit for the indeed/bravo amp(s). check with jeremy to see if it is suitable for your mk2.  this would be a decent upgrade at a very modest price>
 
hth,

 

[Reticuli2]

Tubes and the fostex seem like a terrible idea.
 
And if you're making the t50rp into a closed headphone, wouldn't the t40rpmk2 make more sense?

 

[Naim.F.C]

Ok so I have two pairs of these. One's being modded and one's being left vanilla. Going to do a full comparison to really see just how much of a difference modding makes.

 

[geetarman49]

what experience(s)  prompts you to make such a statement?
i can understand if one has a general dislike for putzing around with tubes ... i did for a very, very long time (think decades).
the amps mentioned in the previous posts are all hybrids, with the tube(s) in the driver stage; outputs are all ss.
 
Quote:

Tubes and the fostex seem like a terrible idea.
 
....

 

 

[leeperry]

 

Ok so I have two pairs of these. One's being modded and one's being left vanilla. Going to do a full comparison to really see just how much of a difference modding makes.

 
It's all placebo.
 
 

 

[joelpearce]

Quote:

Tubes and the fostex seem like a terrible idea.
 
And if you're making the t50rp into a closed headphone, wouldn't the t40rpmk2 make more sense?

It really depends on the nature of the amp itself.  Some tube amps sound great with high impedance headphones, having tons of voltage, but lack the current required for demanding low-impedance headphones.  These are not ideal with the T50RP.  Some, though, deliver exactly what these headphones need, and I know a lot of people love them with hybrid amps.
 
My Musical Paradise MP-301 does a decent job with them, but they sound better out of my SS amp.
 

 

[CYoung234]

Actually, my tube amp drives them very well. It has 2 different impedance settings. I am not quite sure what would prompt you to state the above. I happen to prefer tube amps to most solid state amps. As a data point, I have also used the Fostex phones with a Dynahi. I prefer my tube amp to be honest. My twin brother also has Fostex's and prefers the Dynahi, although he admits they are very close in sound. He is very much a solid state guy, although he built my tube amp for me.
 
Quote:

Tubes and the fostex seem like a terrible idea.
 
And if you're making the t50rp into a closed headphone, wouldn't the t40rpmk2 make more sense?

 

 

[koolkat]

Any place still selling t50rp? 
 
I looked for them a couple of weeks ago, all stores are backordered/out of stock.