 
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
|
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
192.189.187.112
In Reply to: RE: Mullard posted by Jon L on May 11, 2024 at 15:21:45
Most people really need tone controls as bright treble is the bane of a lot of speakers and also excites tinnitus
Follow Ups:
I understand that it would decrease the HF but it would also decrease the load impedance the tube is seeing at those high frequencies and increase distortion produced by the tube. There has to be a better way.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
The effect will be minimal if only very high frequencies are affected. Step networks are common in a lot of gear. Difficult to know whether this is related to the OP's question though, because no one knows what the symptom actually is. Also difficult to know if a step network is appropriate without knowing anything about the circuit. Questions like the first post generally indicate a lack of understanding about tubes.
Edits: 05/13/24
That's a little different.
In your example when C82 goes to zero ohms, the tube is still seeing 15k.
That would not be the case if he "just bypass[ed] the plate resistor with 250 to 500pf cap".
It's not a big deal, I was just pointing that out.
I've also seen phono preamps with "one shot" RIAA filters with impedances so low that the first stage won't stand a chance driving it. In the discussion that followed people were trying to tell me that that is how filters work....by "choking" the tube. :-)
I tried to explain that you can make R1 big enough so A1 (if it were a triode) is not being loaded down. I'm not sure how many understood.
All I'm saying is, you can use a filter to contour the frequency response without placing the tube driving that filter in distress.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
of a component compared to tube flavor. People want/need +/- 3 to 6db and more impact on the frequency response when they are unhappy with the sound. If one brand of tube is "too bright", another brand will not produce a meaningful / measurable difference in frequency response unless one of the tubes is broken. The issue is typically boils down to the frequency response and impedance by frequency of the loudspeakers.
Many guitar amps use the cap across the plate load to smooth out the harsh icepick frequencies they can produce. I have played with bypass caps on the plate load resistors and the impact is pretty subtle in the 250pf range when listening. A shelving resistor, as pointed out, is best.
The reality is that people want and need tone controls but are too scared to have them because the cool kids say they are terrible.
!
The Mind has No Firewall~ U.S. Army War College.
The circuit in my EAR clone is a very neutral one. It clearly shows the different strengths and weaknesses of the tubes I have been rolling thru it.
Anyway, the GE 5751 is out of commission with a broken pin.
I have spent several days auditioning the tubes in different positions, and have found that it sounds the most balanced, warm and true with the stock red-label classic Psvane in V1, the GE 12AX7 in V2, and the RCA 6201 in V3.
I am going to have to dump the RCA do to it having too much emphasis on the edges of metallic objects.
.
Have Fun and Enjoy the Music
"Still Working the Problem"
| FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
||||||||||||||
This post is made possible by the generous support of people like you and our sponsors:
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
