Heya all,
Regretfully I've run into a real bother with my (for me anyway) brand new amp (a Cavalli CTH [Original] DIY'd by a well-known Head-Fi'er, MrSlim, who's been a wonderful help so far but I thought I'd run this by you all as well. My CTH is one of the first prototypes of this amp ever released according to the builder. He says the design has evolved over time so naturally he's also updated a few parts to keep it current as the design evolved.
The other side of this equation of mine are my equally new headphones which also just came in, and they are also DIY, but don't let that scare you. Most everybody knows about the Thunderpants. :) These are Smeggy originals and they work and sound flawlessly. The issue is not with the cans so far as I can tell.
I should note that both the headphones and the amp (along with all the extra tubes for the amp which came as spares) work perfectly fine as far as I can tell, and with no issues that I can detect at low-to-medium volumes only. Classical, jazz, world, rock and similar genres seem to have no issue whatsoever playing, and playing beautifully, so long as you don't crank up the volume (which I'm known to do).
The problem arises when, (full disclosure- I'm one of those crazy bassheads who spent far too much of his youth at all-night dance clubs and raves) When I decide to turn on some Electro, Dubstep, Drum-n-bass, etc. I find myself turning that dial higher and higher until either I hear distortion (which I don't) or it's loud enough to shut out the world and I can happily enjoy the Thunder in my skull, crystal clear but loud. Therein lies the problem though; as I crank that knob up on the amp up to meet my preferred volume, invariably within seconds of hitting some unknown threshold, the amp cuts out, and the little green light which always lights on after about 30 seconds after turning the amp on, goes back to red. Then the only way to get the sound to come back on again is to either turn down the master volume on my DAC (which I generally leave maxed along with foobar) or turn the amp volume knob WAY down before the safety light or whatever it is kicks on and it goes back to green again. Then starts the NEXT process of slowly raising the volume until either I'm happy, or (more likely) it decides to blow again and go back to red and silent.
Just in case this might be useful info, the rest of my chain is as follows- Asus G73JW laptop (foobar2000, minimalist config, playing 85%+ FLAC and some high-bitrate MP3) -- Emu 0404 USB DAC (left&right outputs connected to the amp) -- Cavalli CTH Amp (currently using 6N6P tube) -- Smeggy-crafted "Thunderpants" (Modded-Fostex T50RP)
In case it helps, here are a few troubleshooting steps I've taken-
A. Tried all 6 tubes that came with the amp (2BH7A, 6DJ8,ECC82, and 3 6N6P), no dice. They all cut out and the green light goes to red at high volumes of electronic music. Yes I always remember to flip the switch on the back for 6 or 12 depending on the tube config.
B. In foobar I've tried some things like ASIO but it makes the music sound a lot worse. The distortion using ASIO is palpable, and it sounds much better with the E-mu on DS: Digital Output or DS: Speakers. Also I wasn't able to get WASAPI component installed properly, if that should make any difference.
C. I've tried some other headphones (dynamics are all I have as a basis of comparison at the moment) but the audio-technica ESW9s didnt have the problem, but they also were way too loud and distorted (especially low frequencies) before I got anywhere close to where I tune with the Thunderpants. I feel strongly the issue may have to do with the headphones' planardynamic architecture but I can't imagine how. The kicker of it is, the music sounds to me perfectly clear and accurate all through the spectrum even right before the amp goes it. Like the amp isnt stressing the TPants, it seems the other way around to me.
Anyway, I hope that helps somewhat and you guys have some ideas. Perhaps if I changed to a different tube or something. I'm also of course messaging the nice fellow who I purchased the amp from and he's going to work with me on the issue, so this post may not even be necessary but I thought I'd get it out there and see if anyone had any ideas. If you've experienced this before, please share your experiences!! Thanks so much!
