jlemaster1957
1000+ Head-Fier
Pls see earlier posts in this thread under ‘resistors’ - the approach most of us who do this are using is to place a resistor across the (+) and (-) posts for each channel equal to the resistance that the amp is expecting to see IN PARALLEL to the HP cables attached to the speaker amp binding posts. I myself accomplished this by a Zynsonix adapter box, which does the job neatly if not particularly cheaply, and (as mine is designed) provides 2 four-PIN XLR HP outs, one with no additional resistors in serial to the signal chain (for Susvara and other very insensitive HPs) and the other for more sensitive HPs with serial resistors producing a -12dB difference from the other four-pin out.Alex,
Thank you. I've owned the amp going on 10 years. I wanted to trial with my Calderas prior to buying yet another amp. My current HP amps are less than stellar. Recently moved, so I came upon my owners manual. Yeah, thought to read it.
I use a high class preamp to control volume, so far no issue. Amp appears to run the same temperature as if I'm using my 4ohm speakers. The sound is off the charts and much better than any amp previously used in the home or at shows.
I'll try the new Headamp amp this next week at Capital Audiofest, if stellar, I may buy it versus using the A-70.
Thank you
Note that the parallel resistor will not save your headphones from damage using such a device if you don’t use it carefully and wisely every time (below is my own list of operations in order to minimize risk). The parallel resistor is to protect the amp not the headphones.
Order-
Inserting headphones :
Dac on
Preamp on/ tubes on
Power Amp on
Be sure all music is off and volume is minimal/muted at all stages
Plug in Headphones
Start music and gradually increase volume
To remove:
Mute/ reduce volume
Headphones out
Power amp off
Preamp off
Dac off
Probably better to check this carefully every use.
Avoid changing gain, inputs, or anything else other than volume while HPs are attached to four-pin. If using a turntable, needle drop should proceed unmute/volume adjustment. If you have tubes in the chain be sure that they are quiet and ‘pop’ free.
Some leave the HPs in all the time and just just keep the speaker amp on standby etc. I too skiddish for that, as power on or off can be associated with rapid voltage spikes that could be damaging.
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