I have a very strange problem indeed. I built Kevin Gilmore's CFA3 amplifier, the I added Kevin Gilmore's GRLV linear supply to power it. When I power the amp from a cold start, a high-frequency, almost whistle-like sound shows up on the output. It las a few seconds (longer if it's cold, less if it's hot) and then goes away. While that sound is heard, I can make it go away by touching the 4-pin XLR output socket. Once the amp has been running a while, I can power it off, wait a couple of... Read more ..read more

This headphone amplifier is based on the Tori amplifier, which name seems to come from an agressive dog. I hope to have tamed that dog, hence the name 'Snuggles', Simulating the amplifier in LTspice was not easy for me to get right. I probably should have called this amp 'Struggles' instead of 'Snuggles'. Anyway, I am planning to build it using a NE5532 or similar, but what do you think? Does it have a chance of success ..read more

i "need" to build a headphone amplifier and im limited to these active components, the headphones(iem's) i want to drive are the kinera celest gumiho, the issue i have with them is that theyre 8ohms and my dongle cant keep up current wise during the bass notes ..read more

My dad read a great review in Stereophile about the HiFi Man 1000SE headphones, which had dropped in price. I read online and found they were received very well and called a bargain at $2000. So, I bought them for my dad. However, I also noticed a couple of the reviews were done with the reviewer using EQ on the high frequencies and that many people found them to sound "bright" because of a 6dB high freq. peak from 6-8 kHz. My dad and I were in that camp and he and I had quit listening to... Read more ..read more

I really like the sound of my ESS Heil AMT-1 tweeters. ESS now makes a hybrid headphone using AMT technology. It has a dynamic driver for bass, so it’s a 2-way headphone. Looks well made with walnut cups, real leather pads, metal hardware and removable cord. One complaint was that they are heavy - with all that wood, leather, and aluminum. However, all those premium materials make it feel very well built and high quality. Almost no plastic used. ESS 422H Hybrid Headphones | ESS... Read more ..read more

Hi. I have a uniherz jello star phone with bluetooth 5,3 and some noname bluetooth 5.3 in ears. I wonder if that means automatically that they both support lc3? Also I wonder how its possible to see what codec is being used. I can't find this information on my old Redmi either. Cheers ..read more

This amplifier is based on American Beauty Buffer https://www.diyaudio.com/community/threads/1w-7-components-american-beauty-buffer.331274/ The clever idea is by @diegomj1973 Suitable for 8-64 Ohm headphones. Distortion is low THD 0.0001% The +/-12V supply should be well regulated. Use voltage regulators ..read more

Hello Back in the 70s when the Quad 405 power amp was designed, it seems that little boxes were available that amplified the 405 speaker signal output for a headphone output. The box has a switch that either feeds the speaker signal to the headphones or continues the signal to the speakers. The 405 manual has a simple schematic that shows a provisional design. I thought I would find such a box very easily .. but I have not. Would anyone have an idea where I can find such a thing, preferably... Read more ..read more

All, I'm looking for a service manual or schematic for the STAX SRM 007 T (MK2) amplifier I would like to replace the tubes check and adjust the amplifier Best regards, Bart ..read more

Hello, I'm looking for IEM models to drive with an op-amp with a maximum output current of 45mA (AD4075-2). My source signal is max. 1.5V-peak, so I assume that the ideal load impedance would be 33ohms (1.5/0.045) . Does it make a difference to have impedance matched cans in general, striving for minimal voltage-to-current conversion? I've read that at the end only power matters. If the cans are low in impedance, the excess of voltage from the amplifier will be converted into... Read more ..read more