Search found 3 matches

by djhurley92
Sun Nov 06, 2022 10:06 pm
Forum: Single Ended KT88 Discussion Forum
Topic: Strange issue - occasional low frequency noise in one channel
Replies: 0
Views: 160

Strange issue - occasional low frequency noise in one channel

Hey, I built my KT88 amp following Mark’s videos back in 2020, and have used it as my main amp weekly with no issues. In the last week I’ve had these really strange low frequency noises / energy bursts in the right channel that happen at random. It is difficult to explain so here is a video, the bur...
by djhurley92
Sun Mar 07, 2021 5:02 pm
Forum: Share Your Latest Project
Topic: ECC83 / 12AX7 Phono Pre-amp Project: The Les Box
Replies: 8
Views: 2932

Re: ECC83 / 12AX7 Phono Pre-amp Project: The Les Box

Thanks for that! Here is the schematic, the RIAA is excellent to within 0.1dB. https://i.imgur.com/X8L4vc8.png Only addition I made was to add a mono switch that when closed will sum the outputs (L+R). As there are 1k resistors after the output buffer this seems to work well and doesn't cause any fr...
by djhurley92
Mon Mar 01, 2021 11:08 pm
Forum: Share Your Latest Project
Topic: ECC83 / 12AX7 Phono Pre-amp Project: The Les Box
Replies: 8
Views: 2932

ECC83 / 12AX7 Phono Pre-amp Project: The Les Box

Hey, Prior to following the Blueglow SE KT88 build series last year and building my first SE amp, my first valve project was a point-to-point wired ECC83 (12AX7) phono pre-amp, following the excellent guide written up by Les Carpenter. This is based on a WAD circuit design, and to me sounds really e...