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Gieseler Headphone Amplifier Release

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Hi everyone,

I have been working on a new headphone Amplifier which is finally ready - in stock & priced at $600.

Additionally as it includes RCA line outputs,  it can also function as a basic preamp.

Technical highlights.

Power supply - I have gone totally overboard here as in my opinion the power supply  has a major effect on the sound quality.  Power diodes are a special low radiated noise, very soft recovery types.

Main filter capacitance is a massive 40,000uf using the Nichicon "Gold Tune" KG series, designed specifically for high grade audio equipment.

 Internal regulators are low noise fast transient response Linear Technology devices. These are the same series regulator as the one the Kraftwerk PSU uses.

Amplification is composite design using a LME49600 diamond buffer running in class A coupled to a Muses J-FET operational amp, which also designed specifically for use in audio. At $18 each they cost significantly more than most op-amps.

Gain can be switched between 2x or 6x to cover low or high impedance headphones. RCA sockets are Switchcraft & gold plated.

Power input is from a dual output 9v + 9v external transformer.

 The volume control is a plastic film unit so should have long life.

Relay muting so the unit won't produce any turn on/off pops.

Input impedance is 20k so a nice easy load.

Audio bandwidth is very high & distortion extremely low.

I will post some tech results shortly.

I have just done some quick output level measurements.

Very basic setup with a 1k sign wave, monitoring on a digital scope & taking the voltage measurement just under clipping.

All reading are RMS Milliwatts into stated load.

Into

8   ohms      348 

12 ohms      468

16 ohms      548

33 ohms      720 

600 ohms      50 

As soon as time permits I will take some more precise measurement.

 

IMG_3296.thumb.JPG.49e5687c1dc7c4f6b9e54d96942b59ff.JPGIMG_3306.thumb.JPG.93c510d17a19ec069cb01b57a0df4c02.JPGIMG_3282.thumb.JPG.5401e5d7dd9f766f666ac7d09ceb81b5.JPGIMG_3288.thumb.JPG.61852daedc15258167ba6b530c55c2aa.JPG

Edited by Gieseler Audio
added info

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Hi everyone,
I have been working on a new headphone Amplifier which is finally ready - in stock & priced at $600.
Additionally as it includes RCA line outputs,  it can also function as a basic preamp.
Technical highlights.
Power supply - I have gone totally overboard here as in my opinion the power supply  has a major effect on the sound quality.  Power diodes are a special low radiated noise, very soft recovery types.
Main filter capacitance is a massive 40,000uf using the Nichicon "Gold Tune" KG series, designed specifically for high grade audio equipment.
 Internal regulators are low noise fast transient response Linear Technology devices. These are the same series regulator as the one the Kraftwerk PSU uses.
Amplification is composite design using a LME49600 diamond buffer running in class A coupled to a Muses J-FET operational amp, which also designed specifically for use in audio. At $18 each they cost significantly more than most op-amps.
Gain can be switched between 2x or 6x to cover low or high impedance headphones. RCA sockets are Switchcraft & gold plated.
Power input is from a dual output 9v + 9v external transformer.
 The volume control is a plastic film unit so should have long life.
Relay muting so the unit won't produce any turn on/off pops.
Input impedance is 20k so a nice easy load.
Audio bandwidth is very high & distortion extremely low.
I will post some tech results shortly.
I have just done some quick output level measurements.
Very basic setup with a 1k sign wave, monitoring on a digital scope & taking the voltage measurement just under clipping.
All reading are RMS Milliwatts into stated load.
Into
8   ohms      348 
12 ohms      468
16 ohms      548
33 ohms      720 
600 ohms      50 
As soon as time permits I will take some more precise measurement.
 
IMG_3296.thumb.JPG.49e5687c1dc7c4f6b9e54d96942b59ff.JPGIMG_3306.thumb.JPG.93c510d17a19ec069cb01b57a0df4c02.JPGIMG_3282.thumb.JPG.5401e5d7dd9f766f666ac7d09ceb81b5.JPGIMG_3288.thumb.JPG.61852daedc15258167ba6b530c55c2aa.JPG

Looks nice!! Bad timing for me as I’ve just bought a new HP amp

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Do I need to ask if there is going to be a higher end model? I think there will eventually will be one!

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Hi guys,

 

Richard you are way ahead of me - I’m already thinking of a higher end model but I thought it would be best to start with a basic version.

 

custom_made,

my partner initially fired up the German/English Thesaurus but I thought I would keep it simple for a change.

However still open to suggestions.

 

 

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Clay, suggest putting "Gieseler" in front of your topic title. That way, people will know whose product it is ! 😃 

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Done!

Good suggestion Snoopy.

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Interesting - thanks Mat

 

Quick update.

OK Fein DAC (2v rms out) hooked up to the line inputs & unit being used as preamp into a big T&A power amp.

Gain may be a little high - on low gain getting pretty loud at 11 clock & the same with my Audio Technica ATXH-MX50's.

Gain on the low setting is 1.8x so I might drop that to 1.5x.

Next noise check - super quiet - max vol on high gain I could barley discern the faintest hiss out of the tweeters.

Same with headphones - super quiet.

Channel tracking & imaging nice.

Sound Quality  -  I'm very happy but I need opinions from you guys so one is going to Benjet soon for evaluation.

 

Also I have done a few more quick bench tests.

Line out max level 6v RMS.

Line out impedance  15 ohms

Frequency response

Line out 10Hz to 50KHZ + - .2 dB

Phones  (does depend on load & level)

at 2v out & 33 ohm load 20HZ to 50KHZ + - .3dB

Channel is tracking is pretty good with barely  a deviation from my twin needle audio millivolt meter.

Photo attached of worst case

 

 

IMG_3352.JPG

Edited by Gieseler Audio
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That a pretty cool meter. I use my scope to do that.

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