Hot tip for Tube rolling in the Candela

tommystery · « **Reply #40 on:** 7 Feb 2007, 01:13 am »

I have a tube preamp which uses the 12AX7's (I'm not sure if the tubes are compatible with the candella as I believe that they have a different heater pin voltage) But the comment which I'm trying to make isn't about the tubes themselves but the misconception of industrial tubes. I recently purchased 5751 replacements for the tube preamp (the gain is about 70% of the latter.) these are considered to be "industrial" tubes and are a lot cheaper than the 12AX7 counterparts. I bought 3 GE black plated, 3 mica-spacer varients (considered to be one of the best tubes of the type) for $50 w/ shipping. I have also tried some of the black plate 12AX7, which cost over $50 a tube and they actually sounded less refined and had higher mirophonics than the 5751 varient.

My point to be made; just because a tube is considered to be for "industrial" applications doesn't mean that it won't sound as good or even better in hifi applications. Read some reviews, roll some tubes, but most importantly trust your own ears. =>

AlexG · « **Reply #41 on:** 7 Feb 2007, 10:42 pm »

Quote

12AU7's were originally built for non-hifi applications....

Correct, the ECC82/12AU7 tubes were not originally designed for hi-fi (audio) applications with exception when used earlier on (and today) as a phase inverter in multiple stage audio circuits. They were initially commonly used in deflections circuits in old B&W televisions (remember those?...I used to fix them years ago while attending school). Later on they became popular in hi-fi mainstream applications because of their characteristics specific to having medium gain, wide bandwidth and very low noise... reason for being used in the Candela preamp!

Quote

I have a tube preamp which uses the 12AX7's (I'm not sure if the tubes are compatible with the candella as I believe that they have a different heater pin voltage)

No, the 12AX7's are not compatible with the ECC82/12AU7 used in the Candela preamp. However, both tubes filament voltage characteristics and pin configuration are the same (Vf=6.3/12.6V and If=300/150mA respectively).

Quote

My point to be made; just because a tube is considered to be for "industrial" applications doesn't mean that it won't sound as good or even better in hifi applications. Read some reviews, roll some tubes, but most importantly trust your own ears.

Right on, there is nothing wrong with industrial or better known as JAN (Joint, Army, Navy) tubes. These tubes were manufactured under strict JAN specifications that among other things called for withstanding high level vibrations and physical shock. These tubes were widely used in electronic equipment that among other uses were fitted in war planes including B52's! However, I read a article sometime ago that indicated some tube manufactures at the time would pick their best rated tubes and label them as JAN tubes!

Regards,

Alex

martinr · « **Reply #42 on:** 17 Feb 2007, 04:24 pm »

I swapped out the 1960's GE Hammond ECC82's with a pair of 1950's RCA blackplates (ECC82) that I bought through eBay. The RCA's are slightly sweeter in the high end offering slightly more resolution overall but the Hammond's are a very close second. The great news is that all of these tubes can be had for under $30 a pair -( I paid about $10.00 a pair for the Hammond's plus shipping).
My wife an I both love the sound from the mono SE, candela, Lorelei combo.

THANK YOU KLAUS AND ALEX!!

aa

Martin

marvda1 · « **Reply #43 on:** 17 Feb 2007, 05:14 pm »

don't know how these would sound in the candela but i just got a pair of circa 1950 EI 12au7 for my belles 21a preamp and they blow away the stock mullard cv4003 and a pair of rca clear tops and they only cost me $25 for the pair.

rosconey · « **Reply #44 on:** 18 Feb 2007, 05:53 pm »

i like all the "organ maker" tubes-keep a eye out for baldwin yellow label tubes-you might find the best of bolth the hammond and ge black plates in one aa-
just remember to avoid the early cbs/hytrons-

s_cervin · « **Reply #45 on:** 19 Feb 2007, 10:18 pm »

Quote from: martinr on 17 Feb 2007, 04:24 pm

I swapped out the 1960's GE Hammond ECC82's with a pair of 1950's RCA blackplates (ECC82) that I bought through eBay. The RCA's are slightly sweeter in the high end offering slightly more resolution overall but the Hammond's are a very close second. The great news is that all of these tubes can be had for under $30 a pair -( I paid about $10.00 a pair for the Hammond's plus shipping).
My wife an I both love the sound from the mono SE, candela, Lorelei combo.

THANK YOU KLAUS AND ALEX!!

aa

Martin

How about the bass with the blackplates?

martinr · « **Reply #46 on:** 19 Feb 2007, 10:59 pm »

IMO the bass is as extended with the blackplates as it was with the hammonds. A touch more detail in the lower frequencies overall. The hammonds displayed significant more bass extension than the stock teslas that came with the Candela.

Martin

TomS · « **Reply #47 on:** 23 Feb 2007, 03:00 am »

Anyone know if the Philips Holland E80CC 12au7 variant works in Candela? If so, anyone ever tried them? Tom

TomS · « **Reply #48 on:** 23 Feb 2007, 03:49 pm »

Alex said it would work electrically but is unfortunately almost 3" tall!! Oops, I guess we need a trap door on the top for tube rolling

AlexG · « **Reply #49 on:** 23 Feb 2007, 03:52 pm »

Quote

Anyone know if the Philips Holland E80CC 12au7 variant works in Candela? If so, anyone ever tried them?

The E80CC is a variant to the 12AU7 but is a rare animal because it is 72mm (almost 3") tall! Most ECC82/12AU7 are under 50mm (2") tall.

The Philips Holland E80CC is not recomended to be used in the Candela because you will not be able to close the cover!

Regards,

Alex

TomS · « **Reply #50 on:** 23 Feb 2007, 04:35 pm »

Since I don't have one yet in the flesh this may be obvious, but have you ever thought of putting holes with optional plugs and/or letting them poke through like the Modwright CDP's?? It would make it easy to swap without taking the cover off, assuming that's how it works.

rosconey · « **Reply #51 on:** 23 Feb 2007, 09:27 pm »

they will fit in my candella aa -send them to me and ill rate them for you

thats the nice thing about my custom candella case-easy tube swapping

i think klaus was against a door for access because he was affraid people would drop things inside- but i never listen to anyone so i built mine with a hatch

martinr · « **Reply #52 on:** 3 Mar 2007, 11:23 pm »

I just received a pair of JAN CBS Hytron 5814's WA - best military spec, circa 1955. They sounded good, presentation was forward compared to my RCA 12Au7 blackplates (1950's) but they did not have the sweet tubed sound of the RCA's, decay was probably better than the RCA's although altogether not as musical. The Hytrons were more stereo sounding as opposed to allowing the Lorelies to vanish characteristic of the RCA's. Microdynamics with the RCA's are very good - acoustic guitar strings sound real, vocal timbres are beautiful soundstaging back to front and side to side is fleshed out better with the RCA's than any of the other tubes Ive tried (see below). I do think that tube choice comes down to personal taste, room characteristics, type of music, and other components associated with the Candela.

The order of my my personal favorites so far is:
1. RCA blackplates 1950's - black backround with white RCA lettering $29.00 shipped off eBay
2. 1965/66 Hammond 12AU7 made by G.E. - Very close to the RCA blackplates, not quite as sweet sounding but a nice upgrade to the stock Tesla's. (I have an extra set Ill sell for $20.00 shipped paypal add 3% - PM me if interested)
3. 1955 CBS Hytrons JAN5814WA
4. Candela stock Tesla's
5. New Tesla longplates

I'm sticking with the RCA's until I decide to fork out the dough for some European NOS......later.

The system sounds great!

Martin

Odyssey Stratus Mono extremes, Candela, Lorelei's, Onkyo Integra 6 disc changer, Channel Islands VDA1 and VAC1, Gronenberg, DH labs and Signal Cable cabling.

rosconey · « **Reply #53 on:** 4 Mar 2007, 11:01 am »

are the cbs hytrons new? mine took a day or so before they started sounding great-my hammonds were used and sounded good from the start-

ill take those cbs/hytrons off your hands aa

martinr · « **Reply #54 on:** 4 Mar 2007, 11:18 am »

The Hytrons are new - Ill let em burn in for a day and get back with you.

rosconey · « **Reply #55 on:** 4 Mar 2007, 02:07 pm »

http://www.audiocircle.com/index.php?action=gallery;area=browse;album=746

candella tube rolling made easy

martinr · « **Reply #56 on:** 4 Mar 2007, 04:29 pm »

Rosconey your Candela tube modification is brilliant!!

I like the "tube tray" on top.

Way to go!

Martin

martinr · « **Reply #57 on:** 4 Mar 2007, 06:33 pm »

Quote from: rosconey on 4 Mar 2007, 02:07 pm

http://www.audiocircle.com/index.php?action=gallery;area=browse;album=746

candella tube rolling made easy

BTW - what did you do with the on/off switch?

bunky · « **Reply #58 on:** 4 Mar 2007, 07:51 pm »

Quote from: martinr on 4 Mar 2007, 06:33 pm

Quote from: rosconey on 4 Mar 2007, 02:07 pm
http://www.audiocircle.com/index.php?action=gallery;area=browse;album=746

candella tube rolling made easy

BTW - what did you do with the on/off switch?

I believe that Rosconey has one of the two original prototype Candela's

in slightly different casework and his power switch may be on the back of the Preamplifier

martinr · « **Reply #59 on:** 5 Mar 2007, 12:46 am »

Quote from: martinr on 3 Mar 2007, 11:23 pm

I just received a pair of JAN CBS Hytron 5814's WA - best military spec, circa 1955. They sounded good, presentation was forward compared to my RCA 12Au7 blackplates (1950's) but they did not have the sweet tubed sound of the RCA's, decay was probably better than the RCA's although altogether not as musical. The Hytrons were more stereo sounding as opposed to allowing the Lorelies to vanish characteristic of the RCA's. Microdynamics with the RCA's are very good - acoustic guitar strings sound real, vocal timbres are beautiful soundstaging back to front and side to side is fleshed out better with the RCA's than any of the other tubes Ive tried (see below). I do think that tube choice comes down to personal taste, room characteristics, type of music, and other components associated with the Candela.

The order of my my personal favorites so far is:
1. RCA blackplates 1950's - black backround with white RCA lettering $29.00 shipped off eBay
2. 1965/66 Hammond 12AU7 made by G.E. - Very close to the RCA blackplates, not quite as sweet sounding but a nice upgrade to the stock Tesla's. (I have an extra set Ill sell for $20.00 shipped paypal add 3% - PM me if interested)
3. 1955 CBS Hytrons JAN5814WA
4. Candela stock Tesla's
5. New Tesla longplates

I'm sticking with the RCA's until I decide to fork out the dough for some European NOS......later.

The system sounds great!

Martin

Odyssey Stratus Mono extremes, Candela, Lorelei's, Onkyo Integra 6 disc changer, Channel Islands VDA1 and VAC1, Gronenberg, DH labs and Signal Cable cabling.

After listening to Rosconey and allowing some time for the CBS Hytron tubes to burn in I have to stay I stand corrected.......

THE CBS HYTRON TUBES ARE AWESOME!!!!!
COMPLETE SYSTEM TRANSFORMATION!!!!
HAVE NOT HEARD ANYTHING LIKE THIS SINCE I HAVE OWNED THE ODYSSEY SYSTEM
DETAIL IS INCREADIBLE
SOUNDSTAGE COMPLETELY BLOWN OUT COMPARED TO THE OTHER TUBES IVE TRIED
THESE PUT THE SYSTEM IN A COMPLETELY DIFFERENT LEAGUE THAN BEFORE
HYTRONS GO TO NUMBER ONE ON THE LIST IMHO

GET SOME

ROSCONEY I CANT THANK YOU ENOUGH

- MARTIN