Author Topic: Newbie and Not-so Noob Thread: Questions (FAQ) on anything Tubes (Read 102953 times)

Superman · « **Reply #150 on:** Aug 27, 2005 at 10:20 AM »

hi matt! IMHO and in my limited experience, a tube buffer can either improve or kill your system...it's dependent on system synergy...better try it out first in your system and base it on your ears, if there's an audible improvement, then go for it, bro!

H a n $ · « **Reply #151 on:** Aug 28, 2005 at 09:21 AM »

Quote from: MAtZTER on Aug 27, 2005 at 09:50 AM

Can anyone share their experience with tube buffers? Do they really sound good?

TIA

My AMX preamp have 2 inputs tube buffer and linestage for me my buffer help improve and tame some unwanted harshness or sharpness, provide wider soundstage and depth with good separation and sweet vocals good for solo female/male, big band, instruments, even rock music but also notice since its tame or roll off some frequency it also sounded a little vague compare to its linestage but not in a sense na ngo ngo.

kaya usually i used it with cdp player that are lean and dry sounding or sa DVD player when playing concert DVD.

Kaya just like Jen mention audition mo with your setup total iba iba naman design and circuit of tube buffer and maybe you'll get the right combo for you.

MAtZTER · « **Reply #152 on:** Aug 29, 2005 at 11:21 AM »

Ok, thanks for the answer guys

, but I was actually asking about tube buffers that are used on SS amps. Will they make the sounds coming from SS tube-like?

Where do you buy these things and how much are they?

TIA

Platinum · « **Reply #153 on:** Aug 29, 2005 at 05:23 PM »

Planning to buy Prologue One for my B&W 603. Any advise from owners? Thanks

Audioboy · « **Reply #154 on:** Aug 30, 2005 at 08:38 PM »

Quote from: MAtZTER on Aug 29, 2005 at 11:21 AM

Ok, thanks for the answer guys , but I was actually asking about tube buffers that are used on SS amps. Will they make the sounds coming from SS tube-like?

Where do you buy these things and how much are they?

TIA

mat,

tube buffer, like the musical fidelity x10d , is connected usually after the source but before the preamp. Some use tube preamp for their SS amps purposely to influence the sound of the latter. A lot of folks prefer the hybrid type (tube pre + SS amp) sound. they claim that the combo produces unfatiguing highs, sweet mids and solid lows.

Kamote-Tops · « **Reply #155 on:** Sep 01, 2005 at 08:28 AM »

Quote from: Audioboy on Aug 30, 2005 at 08:38 PM

mat,

tube buffer, like the musical fidelity x10d , is connected usually after the source but before the preamp. Some use tube preamp for their SS amps purposely to influence the sound of the latter. A lot of folks prefer the hybrid type (tube pre + SS amp) sound. they claim that the combo produces unfatiguing highs, sweet mids and solid lows.

sensya na mga bosing.. ano po ba difference ng tube buffer, like the MF x10d from a tube preamp, like the tono preamp?

are there any difference sa sound pag kinabit ko to sa HT receiver?

thanks alot.

Garp · « **Reply #156 on:** Sep 01, 2005 at 02:22 PM »

The tono preamp or any preamp provides sufficient gain to your source signal so that it can be comfortably driven by an amp (or power tubes in a tube amp).

The tube buffer like the x-10d does not ampfliy (its unity gain). The buffer improves the impedance match between the source and your preamp/amp: high input impedance and low output impedance. This way there is no signal loss even for long cables. But in many cases people buy the buffer to get a taste of tube coloration.

odyopayl · « **Reply #157 on:** Sep 01, 2005 at 05:58 PM »

Quote from: Garp on Sep 01, 2005 at 02:22 PM

The tono preamp or any preamp provides sufficient gain to your source signal so that it can be comfortably driven by an amp (or power tubes in a tube amp).

The tube buffer like the x-10d does not ampfliy (its unity gain). The buffer improves the impedance match between the source and your preamp/amp: high input impedance and low output impedance. This way there is no signal loss even for long cables. But in many cases people buy the buffer to get a taste of tube coloration.

Using Tono will make your system warm sounding, but added details (resolution) on the music. Highs & lows are controlled and extended.

Kamote-Tops · « **Reply #158 on:** Sep 02, 2005 at 11:56 AM »

ahhh..so ganun pala yun.

thanks for the input mga sirs!

bumblebee · « **Reply #159 on:** Sep 02, 2005 at 09:01 PM »

Ano ba yung bina-bias, yung tube or yung amp?

MiniCooper · « **Reply #160 on:** Sep 03, 2005 at 12:02 AM »

bumblebee, the term "bias" refer to the maintenance ritual performed on many tube amps.

you are basically making sure that the idling current in the Power Tubes in PushPull output stages is where its supposed to be. Continued use and the inherent characteristics of tubes causes drifts in bias voltage.

Some tube amps have a mechanism to automatically set the bias so you don't have to do anything. If your's don't have it, then it is wise to have a VOM handy to measure and adjust.

Cheers!

bumblebee · « **Reply #161 on:** Sep 03, 2005 at 06:31 PM »

Quote from: MiniCooper on Sep 03, 2005 at 12:02 AM

bumblebee, the term "bias" refer to the maintenance ritual performed on many tube amps.

you are basically making sure that the idling current in the Power Tubes in PushPull output stages is where its supposed to be. Continued use and the inherent characteristics of tubes causes drifts in bias voltage.

Some tube amps have a mechanism to automatically set the bias so you don't have to do anything. If your's don't have it, then it is wise to have a VOM handy to measure and adjust.

Cheers!

Many thanks MiniCooper

I've read somewhere that you do biasing when you change tubes. So kung fixed yung bias points, it is necessary to have "matched" tubes? Tama ba? Daming tanong no?

bumblebee · « **Reply #162 on:** Sep 11, 2005 at 09:47 AM »

Sirs,

How does one know the "operation voltage" of a tube amp? Nasa specs po ba ito? Sorry, nde ko po alam yung proper terminology e

odyopayl · « **Reply #163 on:** Sep 12, 2005 at 08:35 AM »

Quote from: bumblebee on Sep 11, 2005 at 09:47 AM

Sirs,

How does one know the "operation voltage" of a tube amp? Nasa specs po ba ito? Sorry, nde ko po alam yung proper terminology e

It's the specs of every tube (nameplate). Try to "Google it" to know them well.

bumblebee · « **Reply #164 on:** Sep 12, 2005 at 09:41 AM »

Sir,

I was referring to the operational voltage of the amp, not the tube. I came across an article kc about biasing. It said the "safe" bias point is dependent on the operational voltage of the amp.

bumblebee · « **Reply #165 on:** Sep 12, 2005 at 09:58 AM »

Thanks, Sir 2ny

Sorry as I have really messed terms up

I read about an article saying that an EL34 (25W) can be "safely" biased at 44mA (no more than that) at 400V Class AB operation (.7*25W/400V). I'd like to know if "400V" can be found in the specs.

Sorry po ulit

JojoD818 · « **Reply #166 on:** Sep 12, 2005 at 10:10 AM »

I think the ST70's EL34s are biased at around 50mA per tube at a plate voltage of around 410V. You can find these at the ST70's manual.

Most PP cathode bias output sections I've seen have their EL34s at around 390V with a bias current of 70mA per tube, while fixed bias have the opposite, higher plate voltage and lower bias currents. This probably shows the inherent efficiency of fixed bias topologies in Class AB1.

Anyway, I doubt you'll find the plate/supply voltage stamped at the back of the amp, the manual of the amp may have this though. Opening the amp may answer your question, though care must be practiced, the caps may still be charged and maybe enough to injure you. Safety first dude.

Cheers,
JojoD

s2kov · « **Reply #167 on:** Sep 12, 2005 at 10:18 AM »

EL34 on Dynaco ST70 is set to 50mA for each tube.

Quote from: bumblebee on Sep 12, 2005 at 09:58 AM

Thanks, Sir 2ny

Sorry as I have really messed terms up

I read about an article saying that an EL34 (25W) can be "safely" biased at 44mA (no more than that) at 400V Class AB operation (.7*25W/400V). I'd like to know if "400V" can be found in the specs.

Sorry po ulit

bumblebee · « **Reply #168 on:** Sep 12, 2005 at 10:26 AM »

Thanks Sirs JojoD and s2kov

San ba merong Electronics 101? :'(

s2kov · « **Reply #169 on:** Sep 12, 2005 at 10:33 AM »

WAD's KiT34 Integrated Valve Amplifier

Quote from: JojoD818 on Sep 12, 2005 at 10:10 AM

Most PP cathode bias output sections I've seen have their EL34s at around 390V with a bias current of 70mA per tube, while fixed bias have the opposite, higher plate voltage and lower bias currents. This probably shows the inherent efficiency of fixed bias topologies in Class AB1.

Cheers,
JojoD

s2kov · « **Reply #170 on:** Sep 12, 2005 at 10:39 AM »

I have several articles relating to tube amplifier design. Let me know, if your interested.

Cheers!

Quote from: bumblebee on Sep 12, 2005 at 10:26 AM

Thanks Sirs JojoD and s2kov San ba merong Electronics 101? :'(

bumblebee · « **Reply #171 on:** Sep 12, 2005 at 10:51 AM »

Quote from: s2kov on Sep 12, 2005 at 10:39 AM

I have several articles relating to tube amplifier design. Let me know, if your interested.

Cheers!

It'll be very much appreciated

s2kov · « **Reply #172 on:** Sep 12, 2005 at 11:31 AM »

master tony, here it is:

Radiotron: RDH4 http://geek.scorpiorising.ca/
Everything About Screen Grid: http://www.webace.com.au/~electron/tubes/screens.htm

I have several articles from Norman Crowhurst in pdf format.

hanapin ko yung iba!

Quote from: 2ny on Sep 12, 2005 at 11:13 AM

andy,
how about some links?

s2kov · « **Reply #173 on:** Sep 12, 2005 at 11:43 AM »

http://www.tpub.com/content/neets/14178/

odyopayl · « **Reply #174 on:** Sep 12, 2005 at 12:19 PM »

Sir s2kov appreciate the links. Thanks for the inputs you're a big help for DIY'r especially for newbies like me.

bumblebee · « **Reply #175 on:** Sep 12, 2005 at 02:28 PM »

Do amps from Wiredstate or AMX have provisions for biasing?

bumblebee · « **Reply #176 on:** Sep 12, 2005 at 08:05 PM »

Thanks again Sir 2ny

I've been reading and trying (really hard

) to understand the basics. Tube amps seem really interesting and I'm considering trying out one (ipon, ipon, ipon). But the biasing thing is making me have second thoughts. SS kc, plug and play e.

Kung afford ko lang sana yung PrimaLuna :'(

RU9 · « **Reply #177 on:** Sep 13, 2005 at 08:15 AM »

[quote ]
Thanks again Sir 2ny

I've been reading and trying (really hard

) to understand the basics. Tube amps seem really interesting and I'm considering trying out one (ipon, ipon, ipon). But the biasing thing is making me have second thoughts. SS kc, plug and play e.

Quote

I also encountered the same problem before, so I asked around. All WS amps so far are auto biasing--plug and play.

My AMX el84 amp is also auto biasing--plug and play. If you are ready with your budget, you can contact Francis (Vintage Dog) sa wiredstate.com.

For AMX, you can talk directly to Andrew at Phasetron or visit:

http://www.amxtubeaudio.com/

His contact number - nasa web site.

bumblebee · « **Reply #178 on:** Sep 13, 2005 at 08:23 AM »

Auto-biasing like the PrimaLuna? No need for matched tubes?

odyopayl · « **Reply #179 on:** Sep 13, 2005 at 08:35 AM »

What makes the tube amp circuit "Auto biasing"? is this accurate? Does it really no need to have match 2's or 4's for an auto -bias tube amp?