Hi all,

Just received my Lisa, and have a question for owners out there. I'm using it with ue11, and there seems to be an issue with volume.

Apparently when I am turning up the volume from zero, the right side is comes on first, and as i turn it up further, then the left side kicks in. Only till a certain point on the pot does the volume appear to equalize, but it's unbearable for my ears.

What do you guys think?

doesnt sound right man, I dont have any issues with channel imbalance and I use IEM's almost exclusively while on the move with it. and muych more sensitive ones than UE11. you might consider an impedence adapter, but I dont think this is right either way. have you emailed Brad??

not yet. I hope to do so soon. At most I can lay my hands on a PtoS.

When we first e-mailed You wanted an amp to play Hard To Drive Headphones, and you noticed this was hard to find as "portable" This is what Lisa III is designed to Do....Yes some people use IEM's with Lisa!! I do not and IMHO replacing the I-pod amp with a similar separate amp, is a little silly, replacing with LISA III is OverKill with IEM's as a weak Link. however if you feel Triad has misrepresented Lisa as an IEM, amp we will gladly refund your remitance in full once proof of return (ins) mailing.

Hi ColdSky, I have researched this some more since you and many more than we anticipated would like to use IEM's. Who am I to say it is more than you "NEED" so the suggestion is to use an attenuator with IEM's . this will give you more control over the volume as you desire.. The other matter could be a dirty pot. sorry it does happen and cause some noise and maybe a jump in volume at first use but by turning it through the range several times will go away.. Anyway if you have any concerns still prevalent E-mail me.

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Gain is too high. you can use attenuation adapters or maybe contact the guys at triad and ask them if they can mod it for you. I just had Ray Samuels lower the gain on my Raptor because I had the same problem with my 650's, the channels were imbalanced at the beginning of the pot travel and when you get past the imbalance its too loud. Also you may be able to have some one build you a cable designed to attenuate.

I've been using my Lisa and UE-11's almost exclusively for more than a year, so I have quite a bit of experience with this setup. I agree, there is a channel imbalance when turning volume from zero to normal listening levels. However, I find the imbalance goes away well before I get to "normal" listening levels.

Using the very sensitive UE-11's with my Lisa (plus iMod, pvacp) I do find volume adjustments to be very, very sensitive, but not at all unworkable. An attenuator of some sort would be preferred and I am exploring that option as I type, but I've made it for more than a year without and I am quite satisfied.

A quick plug to Brad and the other folks at Triad. Not only do they make the best product I've ever found, but their customer service long after the sale is as good as it gets.

This is a very common problem with potentiometers.

Adding output impedance may have an effect on the sound of your earphones. Your erphones contain a crossover network, so that may not be the best idea.

I know that you can add input impedance before the potentiometer that can accomplish the same task but before amplification.

Just something to consider. I know it works well with other amps.

Like stated above, there's probably nothing wrong with your LISA, it's just how potentiometers are.

I think the best way to solve the problem is to lower the gain, and you should talk to the seller about it. AD744 is unity gain stable, so there should be no problem to lower the value of resistor R4 in the schematic Lisa III Schematics and Specifications
You could parallel R4 with a resistor (something like 3k to get gain 2, and to be safe a small cap - something like 10 pF) via a switch.

Using external attenuators is an option, but not without complications. If you put the attenuator at the output, you'll get high output impedance with a decreased damping factor, worse crosstalk and the frequency response will probably be altered. If you put the attenuator at the input, you'll get more noise, and even without an attenuator I find the noise annoying with a gain of 6 and the resistor values used in LISAIII.

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IEM's are hard to drive, not full size high impedance phones. I don't think many headphone amps are designed for 16R load. When I build an amp, I'll always test it with both high and low Z phones, even with 4R speakers. I know LISAIII can drive low Z phones with grace. By adjusting the gain, I think it could be a good companion to IEM's.