Got a used bargain-price amp a few days ago. For about 90 US$, the used-dealer thought it was solid-state. A discontinued Hughes&Kettner "Studio 84" amp (AKA "Tube 20") HOWEVER
When i play bassy notes a bit louder (clean or dirty) I hear an amplified glass rattling sound. I've read that the taller EL84 are prone to rattle. Even with the amp off, if i give a little knock on the top, i can hear the sound of glass (kinda like a tray-full of empty drinking classes being carried down the hall)
It's annoying and pretty loud. But i open things up and carefully had a look-see. Nothing on the valve or its wire-harness seems overtly loose. But being a combo amp, it will vibrate...
I'm going to send it in cause the valves look original (H&K branded), yet the amp must be at least 10 years old.
Any recommendations to me to get the tech to do? What valves should i NOT accept. I'm hoping for a nice warm, sweet & articulate vibe. Medium gain. Bluesy rock. should i fear Chinese Valves?
At the moment the overdrive channel is quite extreme-face-melt stuff. If i can influence things with valve choice, I'd like to mellow this out just a bit.
Also the amp makes a intermittent breathing, humming sound, along with the glass-chinking-sound.
This is an exerpt from the manual:
Technical Specifications
TUBES: 2x 12AX7A (ECC 83); 2x 6BQ5 (EL84)
Preamp section: CHANNEL 1, CHANNEL 2 tube channels
INPUT: -10 dBV/ 1 MOhm
FX-RETURN: 0 dBV/ 47 kOhms
FX-SEND: 0 dBV/ 220 Ohms
RED BOX D.I. OUT: - 3 dBV/ 220 Ohms
Power amp section: variable power EL84 tube amp
Output Power: 20 W RMS (into 8 Ohms)
Frequency response (1W): 20 Hz - 25 kHz (into 4 Ohms or 8 Ohms)
Speakers: CELESTION Rock Driver Pro, 12", 8 Ohms
Hope any of you tube-heads can help out....
When i play bassy notes a bit louder (clean or dirty) I hear an amplified glass rattling sound. I've read that the taller EL84 are prone to rattle. Even with the amp off, if i give a little knock on the top, i can hear the sound of glass (kinda like a tray-full of empty drinking classes being carried down the hall)
It's annoying and pretty loud. But i open things up and carefully had a look-see. Nothing on the valve or its wire-harness seems overtly loose. But being a combo amp, it will vibrate...
I'm going to send it in cause the valves look original (H&K branded), yet the amp must be at least 10 years old.
Any recommendations to me to get the tech to do? What valves should i NOT accept. I'm hoping for a nice warm, sweet & articulate vibe. Medium gain. Bluesy rock. should i fear Chinese Valves?
At the moment the overdrive channel is quite extreme-face-melt stuff. If i can influence things with valve choice, I'd like to mellow this out just a bit.
Also the amp makes a intermittent breathing, humming sound, along with the glass-chinking-sound.
This is an exerpt from the manual:
Technical Specifications
TUBES: 2x 12AX7A (ECC 83); 2x 6BQ5 (EL84)
Preamp section: CHANNEL 1, CHANNEL 2 tube channels
INPUT: -10 dBV/ 1 MOhm
FX-RETURN: 0 dBV/ 47 kOhms
FX-SEND: 0 dBV/ 220 Ohms
RED BOX D.I. OUT: - 3 dBV/ 220 Ohms
Power amp section: variable power EL84 tube amp
Output Power: 20 W RMS (into 8 Ohms)
Frequency response (1W): 20 Hz - 25 kHz (into 4 Ohms or 8 Ohms)
Speakers: CELESTION Rock Driver Pro, 12", 8 Ohms
Hope any of you tube-heads can help out....
Comment