Hi Guys,
I did a Express build (posted on this forum). What does blocking distortion sound like?? And how do I get rid of it?
Thanks
Blocking distortion. what does it sound like?
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andresound
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Blocking distortion. what does it sound like?
If it sounds good, it is good! Trust your ears
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Stevem
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Re: Blocking distortion. what does it sound like?
If your PI output coupling caps are bigger than .022 than that's one easy place to start.
Any amp that sounds good at low volume with enough Bass ( like set up to 7 or 8 ) will sound like crap if you crank the amp up louder and louder with the Bass set as such.
A amp that is set up right with a good speaker when played flat out will only need the Bass to be up to 3 or 4 at most on the neck pickup.
I find I like to have a low volume Bass boost switch to cut in just like old tube mono or stereo record amps used to have.
If you do a search for Aiken amps site, he has a paper covering dealing with blocking distortion issues!
Any amp that sounds good at low volume with enough Bass ( like set up to 7 or 8 ) will sound like crap if you crank the amp up louder and louder with the Bass set as such.
A amp that is set up right with a good speaker when played flat out will only need the Bass to be up to 3 or 4 at most on the neck pickup.
I find I like to have a low volume Bass boost switch to cut in just like old tube mono or stereo record amps used to have.
If you do a search for Aiken amps site, he has a paper covering dealing with blocking distortion issues!
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
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Reeltarded
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Re: Blocking distortion. what does it sound like?
Blocking distortion sounds like mechanical cutoff. The amp can be very NOT hissy but bang a chord and it goes BLAAAT and stops with no "thub" when you mute, just stops. Sounds like lowend fizz.
It is lowend fizz.
Dod you have grid stoppers on all the gain stages?
It is lowend fizz.
Dod you have grid stoppers on all the gain stages?
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
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andresound
- Posts: 701
- Joined: Mon Dec 01, 2014 8:48 am
- Location: Durban South Africa
Re: Blocking distortion. what does it sound like?
Thanks guys,
The amp is STOCK values for TW express with the exeptioon of;
6K8k for 3rd stage cathode (instead of 10k).
and additional .001uf in parrallel with stock .002uf coupling cap.
Turns out, what i was hearing was a "bad" tube in V1. On inspection the culprit had a broken piece of Mica that had dislodged from the support. Went through my NOS stock again and was battiling to use some of my best sounding mullard C91 LP's in V1 because of microphonics without guitar. Took Glen (guitarpicker) advice and installed a .001uf snubber on 2nd stage plate resistor. Much better!! I can now use the 500pf bright position
Thanks for feedback. Next mission will be to do a sound/video clip.
The amp is STOCK values for TW express with the exeptioon of;
6K8k for 3rd stage cathode (instead of 10k).
and additional .001uf in parrallel with stock .002uf coupling cap.
Turns out, what i was hearing was a "bad" tube in V1. On inspection the culprit had a broken piece of Mica that had dislodged from the support. Went through my NOS stock again and was battiling to use some of my best sounding mullard C91 LP's in V1 because of microphonics without guitar. Took Glen (guitarpicker) advice and installed a .001uf snubber on 2nd stage plate resistor. Much better!! I can now use the 500pf bright position
Thanks for feedback. Next mission will be to do a sound/video clip.
If it sounds good, it is good! Trust your ears
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Reeltarded
- Posts: 10189
- Joined: Sat Feb 14, 2009 4:38 am
- Location: GA USA
Re: Blocking distortion. what does it sound like?
Aha! I chased one of those for an hour last week.
Signatures have a 255 character limit that I could abuse, but I am not Cecil B. DeMille.
Re: Blocking distortion. what does it sound like?
Yeah.andresound wrote: Turns out, what i was hearing was a "bad" tube in V1.
The first step in debugging any tube amp is always to replace tubes with known-good replacement tubes.
Tubes fail more often than any other part in the amp. There's a reason they're in sockets.