It is currently Tue Mar 17, 2020 3:53 am

All times are UTC - 7 hours



Post new topic Reply to topic  [ 6 posts ] 
Author Message
Post subject: Blues Deluxe RI - BIAS - What value u set?
Posted: Wed Oct 26, 2011 8:53 am
Offline
Hobbyist
Hobbyist

Joined: Mon Aug 30, 2010 6:44 am
Posts: 7
Hi friends,

I'm changing bias on BDRI searching for a better sound...
Let's do a research...
Please post what value u set/measured at BIAS TEST POINT and with what TUBE.

Thx :)

Mine BDRI with GT Blue = 63mV


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: Blues Deluxe RI - BIAS - What value u set?
Posted: Wed Oct 26, 2011 12:56 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Tue Jun 29, 2010 1:20 pm
Posts: 9640
Location: Indiana
Hi BluesmanRS,

I have the HRDlx (very similar), and have the original GT Red @ 78 mV

_________________
---> "The amp should be SWITCHED OFF AND UNPLUGGED before you do this!" <---

Por favor, disculpe mi español, no se llega a la práctica con mucha frecuencia.


Top
Profile
Post subject: Re: Blues Deluxe RI - BIAS - What value u set?
Posted: Wed Oct 26, 2011 1:22 pm
Offline
Rock Star
Rock Star

Joined: Mon Apr 05, 2010 2:37 pm
Posts: 8708
Location: Natural Bridge, Virginia
BluesmanRS wrote:
Hi friends,

I'm changing bias on BDRI searching for a better sound...
Let's do a research...
Please post what value u set/measured at BIAS TEST POINT and with what TUBE.

Thx :)

Mine BDRI with GT Blue = 63mV


Saying that you have the bias set at 63 mv for a particular tube is totally meaningless. You also have to know the plate voltage and recognize that the bias point measurement represents the cathode current of two tubes, so the actual cathode current is approximately half of what you are measureing (You are measuring across a 1 ohm, 5% tolerance resistor so 1 mv = approximately 1 ma). Also you are actually concerned with the plate current (which is close enough for government work to the cathode current). Knowing these values you can calculate the percentage of the maximum plate dissipation. Anywhere between 50% and 70% of maximum plate dissipation is ok.

Having said that, my measured cathode current per tube (JJ 6L6GC) is 38 ma (which corresponds to about 36 ma plate current) at a plate voltage of about 414 volts giving me 50% max plate dissipation. The measurement at the Fender test point is 83 to 85 mv. My BDRI sounds great. :D

_________________
Bill

Image


Top
Profile
Post subject: Re: Blues Deluxe RI - BIAS - What value u set?
Posted: Wed Oct 26, 2011 2:58 pm
Offline
Professional Musician
Professional Musician

Joined: Sun Dec 19, 2010 12:00 pm
Posts: 1389
With original GT (sovteck) 63mV, I've a pair of JJ since 1 year but not enough time to perform tests, I let you know if I've time this WE.
I saw a very different medium change on the amp with V1 (ECC83) between Sovteck - JJ and Mesa

_________________
Tissan

*'52 Telecaster RI, '57 Stratocaster RI, Gibson ES175 RI, Washburn Hawk 1980, Epiphone Casino MIK 2000, 57' Deluxe Knotty Alder, BDRI ...*
https://soundcloud.com/pierrou
http://www.youtube.com/user/Jazzenfamille


Top
Profile
Post subject: Re: Blues Deluxe RI - BIAS - What value u set?
Posted: Wed Oct 26, 2011 3:28 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Fri Feb 05, 2010 4:31 am
Posts: 14050
Location: Province de Québec, Canada
+100 Bluesky636


Top
Profile
Post subject: Re: Blues Deluxe RI - BIAS - What value u set?
Posted: Wed Oct 26, 2011 3:53 pm
Offline
Rock Icon
Rock Icon
User avatar

Joined: Wed Mar 31, 2010 12:48 am
Posts: 26417
Location: Tombstone Territory
stratele52 wrote:
+100 Bluesky636


+101

:mrgreen:

Arjay

_________________
"Here's why reliability is job one: A great sounding amp that breaks down goes from being a favorite piece of gear to a useless piece of crap in less time than it takes to read this sentence." -- BRUCE ZINKY


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 6 posts ] 

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: