Author Topic: AMX Tube Products (Read 680043 times)

j_albert22 · « **Reply #1560 on:** Jun 16, 2004 at 03:20 PM »

Quote from: s2kov on Jun 16, 2004 at 03:12 PM

If you're using the same specs of power trafo and you're only one using 5AR4 tube. Andrew might give you a preamp operating on different operating point. I assume that operating the preamp using 5U4G gives you the sonic quality rather than running the preamp with higher B+..... Just remember, running the the tubes on higher B+, you're also running it on a near distortion....

one thing that affect sound quality using both rectifier tube is the voltage drop of the tube.. i think mas malaki voltage drop nang 5U4G kaya medyo lumalambing or bumabagal rather than 5AR4.....

akyatbundok · « **Reply #1561 on:** Jun 16, 2004 at 03:25 PM »

siguro nga bro that's why i got improved sonics with the 5u4g..... teka lugi yata ako coz i had to get me a 5u4g from "tube suki" isak

nahhhh.... di naman siguro, i checked the net for prices, it turns out the matsushjtas are more expensive..... i saw a matsu 5ar4 sold within 1hr in wiredstate for 2k.

vvt-i · « **Reply #1562 on:** Jun 16, 2004 at 03:27 PM »

quoted from sir andrew:

"I use standard GZ34 Matsucrapa NOS in original box not in deceiving generic white boxes. I do not have RCA5U4G, and 5U4G will not be able to handle 4 6550's or KT88's. The ones I could find are mostly used with very little juice left in them, and power amps are demanding.
I do like to take my chances. Preamps will be no problem for this used tubes, the power demand is minimal, even 10% power only is left of the rectifier tube it will still be fine. Sylvania 5U4GB is OK also and can be purchased in JAN boxes, pero lately could not find any. Last one I had , I have used in the preamp of Henry."

s2kov · « **Reply #1563 on:** Jun 16, 2004 at 03:28 PM »

Pwede pa naman ya'ng 5AR4 tube mo eh! Dropping resistor lng katapat nyan!!!!

Quote from: akyatbundok on Jun 16, 2004 at 03:25 PM

siguro nga bro that's why i got improved sonics with the 5u4g..... teka lugi yata ako coz i had to get me a 5u4g from "tube suki" isak nahhhh.... di naman siguro, i checked the net for prices, it turns out the matsushjtas are more expensive..... i saw a matsu 5ar4 sold within 1hr in wiredstate for 2k.

akyatbundok · « **Reply #1564 on:** Jun 16, 2004 at 03:36 PM »

thanks for the quote "push-pull master" jetok.

parang ganun din ang narinig kong advice kay sir tony aka joan2, pagdating sa mga preamps mas forgiving bcoz of low power requirements so no worries tatagal daw kahit medyo piga ng konti.... but tube amps are a different ballgame.

kaya pala, naubusan ng 5u4g si sir andrew.... masaya naman ako i have an extra matsu 5AR4 tamang-tama sa next project ko na push-pull hehe.

bradir s2kov, ano yan dropping resistor, para ma-lower ang B+ so paparehas na sa 5u4g?

slayer · « **Reply #1565 on:** Jun 16, 2004 at 03:38 PM »

Blowout ka naman master Hans!!

Quote from: jetok on Jun 16, 2004 at 03:27 PM

quoted from sir andrew:

is left of the rectifier tube it will still be fine. Sylvania 5U4GB is OK also and can be purchased in JAN boxes, pero lately could not find any. Last one I had , I have used in the preamp of Henry."

Superman · « **Reply #1566 on:** Jun 16, 2004 at 03:46 PM »

anyone tried the hard-to-find Mullard 5U4G (i think it's also the CV7008)...the best rectifier tube i've used so far!!!...it also optimizes your power tubes and yet prolongs the life of your power tubes...thanks!

H a n $ · « **Reply #1567 on:** Jun 16, 2004 at 03:50 PM »

Quote from: Superman on Jun 16, 2004 at 03:46 PM

anyone tried the hard-to-find Mullard 5U4G (i think it's also the CV7008)...the best rectifier tube i've used so far!!!...it also optimizes your power tubes and yet prolongs the life of your power tubes...thanks!

Sir meron ata si DON ST paldO kimpao ng mullard 5u4G i can't remember when i heard it.. pero maganda!!!

Quote from: slayer on Jun 16, 2004 at 03:38 PM

Blowout ka naman master Hans!!

Master Slayer,

Wag na ubos na moolahhh sa pa tweak hehehhee

akyatbundok · « **Reply #1568 on:** Jun 16, 2004 at 03:55 PM »

Quote from: Superman on Jun 16, 2004 at 03:46 PM

anyone tried the hard-to-find Mullard 5U4G (i think it's also the CV7008)...the best rectifier tube i've used so far!!!...it also optimizes your power tubes and yet prolongs the life of your power tubes...thanks!

oooh mama... mullard 5u4g £75.00 on ebay.uk

i just read that nos 5u4g's from 40's/50's have less forward resistance and higher B+ thus more headroom.

kimpao · « **Reply #1569 on:** Jun 16, 2004 at 03:58 PM »

Quote from: akyatbundok on Jun 16, 2004 at 03:55 PM

oooh mama... mullard 5u4g £75.00 on ebay.uk

i just read that nos 5u4g's like the rca sexy bottle have lower forward resistance and higher B+ thus more headroom.

I think mullard imposes this particular technique in all their tubes especially on rectifiers.

BTW, master ala tayo 5U4G, Mullard GZ34/5AR4 meron.

kimpao · « **Reply #1570 on:** Jun 16, 2004 at 04:05 PM »

Mga SARS ay este............SIRS OT na tayo niyan. Na sita tayo dun sa previous page, gawa tayo bago thread para sa "Tubo".

s2kov · « **Reply #1571 on:** Jun 16, 2004 at 04:12 PM »

Exactly, you don't need to replace 5AR4 tube just determine your load current to compute for dropping resistor.

5U4G = 5AR4 + Dropping Resistor

Voila, you will have the same operating point as John/Hans preamp....

Quote from: akyatbundok on Jun 16, 2004 at 03:36 PM

bradir s2kov, ano yan dropping resistor, para ma-lower ang B+ so paparehas na sa 5u4g?

H a n $ · « **Reply #1572 on:** Jun 16, 2004 at 05:00 PM »

Quote from: kimpao on Jun 16, 2004 at 03:58 PM

I think mullard imposes this particular technique in all their tubes especially on rectifiers.

BTW, master ala tayo 5U4G, Mullard GZ34/5AR4 meron.

Opsss sorry my mistake..

Audioboy · « **Reply #1573 on:** Jun 17, 2004 at 10:53 AM »

Quote from: s2kov on Jun 16, 2004 at 02:15 PM

Changing rectifier tube from 5AR4 to 5U4G will also change the operating point of the preamp. is the sonic quality improves?

sonic quality changes but it does not warrant improvement. because of the changes in the operating point, either hihina or lalakas kuryente. dont play around with this without expert advice, kasi other parts of the amp may be damaged.

be sure to roll tubes that are within the specifications of your amp.

if you cant resist tube rolling, the best candidate would be the driver tubes. youll notice big difference, if not improvement, in the sonic performance.

the least candidate would be the rectifier tube.

sir arnoldc may have something to say about this topic.

caveat: i may be wrong

s2kov · « **Reply #1574 on:** Jun 17, 2004 at 11:16 AM »

Juls,

As long as you know the limits and specs of your tubes and other parts, you don't have to worry that it will damage. Operating point is a big roll here since you're playing the tube with reference to its transfer curve and in accordance to its maximum power dissipation....

Quote from: JulsP168 on Jun 17, 2004 at 10:53 AM

sonic quality changes but it does not warrant improvement. because of the changes in the operating point, either hihina or lalakas kuryente. dont play around with this without expert advice, kasi other parts of the amp may be damaged.

s2kov · « **Reply #1575 on:** Jun 17, 2004 at 11:21 AM »

As posted earlier, you have to consider the limits of the load or the driver tube. Otherwise, it will damage your tube due to excessive voltage.

JojoD818 · « **Reply #1576 on:** Jun 17, 2004 at 11:58 AM »

Hhmmm... ganun pala yun....

s2kov · « **Reply #1577 on:** Jun 17, 2004 at 12:06 PM »

JojoD,

Para'ng nde mo alam ah!!!!

Quote from: JojoD818 on Jun 17, 2004 at 11:58 AM

Hhmmm... ganun pala yun....

j_albert22 · « **Reply #1578 on:** Jun 17, 2004 at 12:16 PM »

Quote from: JojoD818 on Jun 17, 2004 at 11:58 AM

Hhmmm... ganun pala yun....

kunwari lang yan mamaya babanat din yan .......................pis tayo

akyatbundok · « **Reply #1579 on:** Jun 17, 2004 at 12:52 PM »

going back to the amx topic........... hehehe OT na tayo

guys, para malinaw lang ha..... i hope that my comments re changing the rectifier tube on my amx preamp is not taken too generally, i was talking about my own specific amx preamp, certainly not tube preamps in general.... it is wrong to assume that any circuit will improve by doing the same.... sorry guys if that was the the impression i created.

to further beat the dead chicken

hehehehe.

be careful when tube rolling that you do not push the circuit beyond its limits.

arnoldc · « **Reply #1580 on:** Jun 17, 2004 at 12:57 PM »

juls, andy, nasabi nyo na eh.

i take rectifier change with a grain of salt. tulad ng mga nasabi na, you change the recitier to a different one, you alter the operating point, hence changing the sound.

if you want to have a solid change in your amp, change the output transformer. my 45 was ok with a local transformer with U.S. core, but after replacing it with a tamura, ibang usapan na. also the driver tubes can bring more sonic improvement/change as well as the power tube. ingat lang sa substitue, like a lot of people subs a 5693 to a 12AU7 not knowing na 150 V lang max Vp nun. kung sa foreplay na pre-amp pwede pero sa ibang circuit sunog yang tube na yan.

and as s2kov pointed out, tubes are matibay, i have my Sovtek 2A3 configured with a B+ 20% over the dissipation buhay pa din, pero hindi ko gagawin yun kung RCA na 2A3 noh.

JojoD818 · « **Reply #1581 on:** Jun 17, 2004 at 05:05 PM »

Quote from: akyatbundok on Jun 17, 2004 at 12:52 PM

to further beat the dead chicken hehehehe.

Bro I love to eat chicken too. Hhmm... pero how do you beat a dead chicken?

Fish tayo sir akyat!

JojoD818 · « **Reply #1582 on:** Jun 17, 2004 at 05:14 PM »

Quote from: s2kov on Jun 17, 2004 at 12:06 PM

JojoD,

Para'ng nde mo alam ah!!!!

Kaya nga read lang ako sa inyo kasi dami ko natutunan eh.

From what I leaned (hanep!), plug in the original 5AR4 and then measure the DC and then plug in the 5U4G and then adjust to get the same DC output as the 5AR4 via resistor or choke.

Hhmmm... tama kaya?

akyatbundok · « **Reply #1583 on:** Jun 17, 2004 at 05:15 PM »

yan kasi ang expression ng boss ko sa meeting: "let's keep beating this dead chicken".

hehehe... chicken na may fish pa

interesting idea yun suggestion ni s2kov, kaso pag ginawa yun, di ko na magagamit yung "sexy bottle" ko? gusto ko pa naman yun kasi sexy hehe.

JojoD818 · « **Reply #1584 on:** Jun 17, 2004 at 05:17 PM »

Quote from: j_albert22 on Jun 17, 2004 at 12:16 PM

kunwari lang yan mamaya babanat din yan .......................pis tayo

uy di naman ako babanat, nakikinig lang baga. pis tayo bro!

JojoD818 · « **Reply #1585 on:** Jun 17, 2004 at 05:21 PM »

Quote from: akyatbundok on Jun 17, 2004 at 05:15 PM

yan kasi ang expression ng boss ko sa meeting: "let's keep beating this dead chicken".

hehehe... chicken na may fish pa

interesting idea yun suggestion ni s2kov, kaso pag ginawa yun, di ko na magagamit yung "sexy bottle" ko? gusto ko pa naman yun kasi sexy hehe.

eh di lagyan ng switch para switcheable (tama ba spelling?) between 5AR4 & 5U4G!!!

Give me a dead chicken and I'll practice beating it!

PS. Sensya na mga bro, was reading a Randy Slone book and it's driving me crazy.

s2kov · « **Reply #1586 on:** Jun 17, 2004 at 05:26 PM »

Kung sabagay walang korte yung 5AR4 diretso lng, nde katulad ng 5U4g may korte, seksssiiiiiii.....

Hehehehee....

Quote from: akyatbundok on Jun 17, 2004 at 05:15 PM

interesting idea yun suggestion ni s2kov, kaso pag ginawa yun, di ko na magagamit yung "sexy bottle" ko? gusto ko pa naman yun kasi sexy hehe.

JojoD818 · « **Reply #1587 on:** Jun 17, 2004 at 05:27 PM »

Quote from: s2kov on Jun 17, 2004 at 05:26 PM

Kung sabagay walang korte yung 5AR4 diretso lng, nde katulad ng 5U4g may korte, seksssiiiiiii..... Hehehehee....

Hhmmm... mahilig sa seksi si....

s2kov · « **Reply #1588 on:** Jun 17, 2004 at 05:32 PM »

Jo,

Kmusta project mo? Tube phono stage na ba?

Quote from: JojoD818 on Jun 17, 2004 at 05:27 PM

Hhmmm... mahilig sa seksi si....

JojoD818 · « **Reply #1589 on:** Jun 17, 2004 at 05:39 PM »

Quote from: s2kov on Jun 17, 2004 at 05:32 PM

Jo,

Kmusta project mo? Tube phono stage na ba?

Wala pa ako dun bro, puro gainclones at sub ang projects ko ngayon. No time for personal projects yet. Full featured line-stage muna bago phono.