[shotgunshane]

Do you know how the quickstep compares to the portaphile 627/627x? That would be an interesting comparison.

I haven't had the opportunity to hear the Portaphile.

 

[maguire]

Now that is one sweet rig.......Congratulations Shotgunshane, you have hit the motherload.....

 

[shotgunshane]

Ha, thanks!

Using the TG334 and swapping out from the QS and Slim. Yep, the slim goes on the market today. The pico slim is a really good iem amp but the QS just does everything better but form factor; and even that isn't too far off, especially considering there is a 9v battery in it. Very pleased.

 

[wormsdriver]

Quote:

Ha, thanks!

Using the TG334 and swapping out from the QS and Slim. Yep, the slim goes on the market today. The pico slim is a really good iem amp but the QS just does everything better but form factor; and even that isn't too far off, especially considering there is a 9v battery in it. Very pleased.

my thoughts exactly

 

[tsvo614]

Wow! The cypher labs algorythm is awesome with the quickstep! This is a great combo! nomore distortion at high volumes and the clarity is all there!

 

[cooperpwc]

Glad that you like the Quickstep, Shane.

 

[yates7592]

Hello all. I just ordered a discounted 2stepdance from Jan for a great price. But I am now worried by the potential RF interference issue and am wondering if I should have gone for the Quickstep. Is the 2stepdance more prone to intereference than other portable amps, or all they all? Does your rig set up affect it? I will be using Sony PCM-M10 > Qables gold mini-mini interconnect > 2stepdance > Ety ER4's. Thanks for any advice!  

 

[vwinter]

Not speaking from experience (going straight for the QS), but your source, the PCM-M10, wouldn't be emitting any RFs to begin with, so it shouldn't be a problem for you?

The 209 opamp is kind of known for being prone to picking up RF interference, which is why RF filtering was added to the QuickStep.

 

[yates7592]

Quote:

Not speaking from experience (going straight for the QS), but your source, the PCM-M10, wouldn't be emitting any RFs to begin with, so it shouldn't be a problem for you?

The 209 opamp is kind of known for being prone to picking up RF interference, which is why RF filtering was added to the QuickStep.

 
Thanks for the reply. I was worrying more about mobile cellphone interference - on the train, bus, etc etc.
 
By the way, what is the '209 opamp'?

 

[vwinter]

I'd be interested to know if it would actually pick up RF signals for something not connected to it too.

The OPA209 are the Texas Instruments amplification chips used in the 2Stepdance and Quickstep.

 

[vwinter]

Does anyone know what the mW per channel output at various, or any, Ohm loads is on the Quickstep, using high gain I guess?

 

[yates7592]

I always assumed a portable headphone amp could pick up cellphone interference much like some microphone preamps do, even though not directly connected in the signal chain, just the proximity effect?

 

[vwinter]

I would like to think it wouldn't be that bad. Hopefully someone having experience with the 2Stepdance will chime in soon.

 

[zilch0md]

Quote:

I always assumed a portable headphone amp could pick up cellphone interference much like some microphone preamps do, even though not directly connected in the signal chain, just the proximity effect?

 
Hi,
 
Given that radiation falls off with the square of the distance, proximity is indeed the issue with interference from cellphones, but we're talking about distances of a few inches or less being a problem, potentially.  I use the original (unshielded) Stepdance with a PCM-M10 (for over two years, now) and have never heard any RFI, but I haven't really conducted any tests with a cellphone nearby, nor have I had any experience with your 2Stepdance.  But, I'm at least optimistic that that as long as you don't intend to use a smartphone in close proximity (as in stacked-with) your 2Stepdance, you'll be fine.
 
Oh, and welcome to the very small family of PCM-M10 owners who use it as a DAP!  

 
Mike

 

[zilch0md]

Quote:

Does anyone know what the mW per channel output at various, or any, Ohm loads is on the Quickstep, using high gain I guess?

 
It varies with the Supply Voltage (Vs), but it's almost 1.0 Watt peak-to-peak per channel into 16 Ohms with the the Stepdance family of amps using 15V external power or about 500 mW peak-to-peak on a 9V battery.  
 
For Watts rms, multiply the peak-to-peak wattages by 0.71.   So, figure about 710 mW rms per channel on 15V power (into 16 Ohms) or 355 mW rms on a 9V battery (into 16 Ohms).
 
These are rough estimates, based on calculations I tried to do a couple of years ago.
 
For headphones of higher impedance than 16 Ohms, use a proportion to get in the ball park.  Here's an example for 50-Ohm headphones: 
 
 
 
[size=10.0pt]16 Ohms       x mW rms[/size]
[size=10.0pt]-------  =  -----------[/size]
[size=10.0pt]50 Ohms     710 mW rms[/size]

 
 
 
x = 16 * 710 / 50 = 227 mW rms   (into 50 Ohms, with 15V external power)
 
 
I don't think the PCStep has as much power as the 2Stepdance or Quickstep, because Dr. Meier used fewer paralleled OPA209s in that design (presumably to make room for the DAC circuitry).
 
Take all of this with a big grain of salt.  

 
Mike