Review: Woo Audio WA6 vs. WA6SE (stock units)
Dec 28, 2008 at 4:31 PM Post #271 of 508
Takezo:

You say that the 6fd7 is better than the 6ew7. But, have you got any 6ew7 clear-top?

I have got several 6ew7 and the clear-top is clearly better than normal 6ew7. I will try the thin bottle 6ew7 and i will post the results here.
 
Dec 28, 2008 at 5:39 PM Post #273 of 508
yes, i have clear top 6ew7 and they're fine. the 6fd7 is preferable;
i won't say "better" since i can only speak for myself, but it has
mid and sub bass that is preferable than what the 6ew7, clear top or
otherwise, presents. but you should judge for yourself and not
rely on my limited impressions. the 6fd7 are similar or lower in price
than the 6ew7 so it may be worth while to experiment.
 
Dec 28, 2008 at 7:19 PM Post #274 of 508
Quote:

Originally Posted by takezo /img/forum/go_quote.gif
yes, i have clear top 6ew7 and they're fine. the 6fd7 is preferable;
i won't say "better" since i can only speak for myself, but it has
mid and sub bass that is preferable than what the 6ew7, clear top or
otherwise, presents. but you should judge for yourself and not
rely on my limited impressions. the 6fd7 are similar or lower in price
than the 6ew7 so it may be worth while to experiment.



I have already bought a pair of RCA thin bottle 6fd7 and a pair of RCA fat bottle 6fd7. Moreover a pair of RCA thin bottle 6ew7. Sclamb say that they are better than GE 6we7 (that are clear-top).

In 6fdt, Is the clear-top clearly better than normal like happened in 6ew7?

Of course the sound is very subjective and it depend much of synergy of the system. But i think the personal opinions give always clues.
 
Dec 29, 2008 at 4:13 AM Post #275 of 508
i'm not certain that all "clear" bottle types are "better" than the
top getter tubes. the earlier 50's type are all top getter types and
they were made during the heydays of tube manufacturing... but
if one prefers a clear top for their sound signature it's just as valid.

there's really only one way to find an answer to your question:
try and judge for yourself. i would purchase in small quantities to
test them and if you find one type you definitely prefer, then
purchase in larger quantity if you desire. good luck.
 
Dec 29, 2008 at 6:51 PM Post #276 of 508
Quote:

Originally Posted by takezo /img/forum/go_quote.gif
i've only tried rca and sylvania brands of the 6fd7. not much difference except
the fatbottle of the rca seems to have a slightly sweeter tone than the slim
bottle version. (10+ hrs. of burn-in is recommended for best sound.)

the 5v4ga is thicker sounding to me compared to the 5v4g. the latter sounds
a bit more transparent and a bit more open at the top. great for senn cans
but slightly unfocused with gs1000 and d5000. it could just be that the 5v4g is
much more burnt-in than the 5v4ga that i have... both were "NOS" when i
purchased but i've no way of verifying this.

the 5r4ga is similar as above, in that it too sounds "thicker" in the mid to
sub-bass region and less transparent than the 5r4gy, especially the brimar
version.

there's nothing bad about 5u4g... i just find most of the usa brands to sound
uncontrolled at the bottom. the roundbase english versions seems to sound
more controlled though, but much more expensive... may not be worth it
especially if you like the common 5u4g sound signature.

again, this is with units that have john's pdps modification... i forget how the
stock wa6 sounded...



Thanks again takezo
 
Jan 3, 2009 at 11:55 AM Post #279 of 508
Quote:

Originally Posted by takezo /img/forum/go_quote.gif
yes, i have clear top 6ew7 and they're fine. the 6fd7 is preferable;
i won't say "better" since i can only speak for myself, but it has
mid and sub bass that is preferable than what the 6ew7, clear top or
otherwise, presents. but you should judge for yourself and not
rely on my limited impressions. the 6fd7 are similar or lower in price
than the 6ew7 so it may be worth while to experiment.



I now have the fat bottle RCA 6fd7 tubes. They are definitely better than the cleartop GE 6ew7 tubes. Great bass, wide soundstage and lots of air between the instruments. Definitely will be a favourite tube in the WA6SE. They are an improvement over the RCA thin 6ew7 tubes too as they sound more defined with a more airy sound.

Just one problem. The GE 6ew7 and RCA 6ew7 are dead silent, even with the volume turned up to max and the music paused. The 6fd7 have some backgound static with the volume turned all the way up (that faint ssshhhhhh sound). They are not black and silent like the other tubes.

Has anyone else found this with the 6fd7 tubes?

Simon
 
Jan 3, 2009 at 12:38 PM Post #280 of 508
Quote:

Originally Posted by sclamb /img/forum/go_quote.gif
I now have the fat bottle RCA 6fd7 tubes. They are definitely better than the cleartop GE 6ew7 tubes. Great bass, wide soundstage and lots of air between the instruments. Definitely will be a favourite tube in the WA6SE. They are an improvement over the RCA thin 6ew7 tubes too as they sound more defined with a more airy sound.

Just one problem. The GE 6ew7 and RCA 6ew7 are dead silent, even with the volume turned up to max and the music paused. The 6fd7 have some backgound static with the volume turned all the way up (that faint ssshhhhhh sound). They are not black and silent like the other tubes.

Has anyone else found this with the 6fd7 tubes?

Simon



Likely the result of their much higher "mu" / gain. Not likely a problem with the tube. Jack indicated they could have a higher noise level, but that it should not be noticeable at normal volume levels.
 
Jan 3, 2009 at 1:59 PM Post #281 of 508
Quote:

Originally Posted by Gradofan2 /img/forum/go_quote.gif
Likely the result of their much higher "mu" / gain. Not likely a problem with the tube. Jack indicated they could have a higher noise level, but that it should not be noticeable at normal volume levels.


Definitely not noticeable at normal levels. A good tube
biggrin.gif
 
Jan 3, 2009 at 4:05 PM Post #282 of 508
On my 6 with wall the modifications I actually notice a lower noise floor when using the 6FD7. I am not sure yet if it is my cup o tea but time will tell and I have noticed some changes of the tube as I burn it in (about 10 hours). The mids are more prominent and I do like the Open sound of the tube. Also, I have much, much more gain now, which is welcome with my low output dac of only 1.5 volts.
 
Jan 3, 2009 at 4:43 PM Post #283 of 508
Quote:

Originally Posted by sclamb /img/forum/go_quote.gif
I now have the fat bottle RCA 6fd7 tubes. They are definitely better than the cleartop GE 6ew7 tubes. Great bass, wide soundstage and lots of air between the instruments. Definitely will be a favourite tube in the WA6SE. They are an improvement over the RCA thin 6ew7 tubes too as they sound more defined with a more airy sound.

Just one problem. The GE 6ew7 and RCA 6ew7 are dead silent, even with the volume turned up to max and the music paused. The 6fd7 have some backgound static with the volume turned all the way up (that faint ssshhhhhh sound). They are not black and silent like the other tubes.

Has anyone else found this with the 6fd7 tubes?

Simon



i've noticed the same as well on the wa6SE. using a 6fd7, 6dr7 or 6cy7, the
volume range for normal listening is reduced to 7 o'clock position to 9 o'clock
for my senn hp. and 8 o'clock to 11 o'clock for the denon d5000.
these output tubes do give a faint hiss noise after 12 o'clock position on the
wa6SE (with the senns) but no noise that i can detect on the highly modified
wa6. this is with a relatively high output voltage from my source of 2.25vrms.

for the wa6SE users, i think using the low impedance jack is recommended
with these output tubes; it'll lower the hissing past noon position, which is
too loud for normal listening anyway, imo (it's louder than a rock concert venue).

these amps sound so good after a 2hr. warm up period with these output
tubes. the rca sounds thicker and lusher in the mids, whereas the sylvania
and raytheons sound more neutral and thin, generally speaking.

with some socket adapters i think i can make use of 4 or 5 other output
duo-triode tubes that have similar electronics but differently arranged
pin-outs. will work on these in the upcoming months.
 
Jan 6, 2009 at 4:47 PM Post #284 of 508
Quote:

Originally Posted by takezo /img/forum/go_quote.gif
i've noticed the same as well on the wa6SE. using a 6fd7, 6dr7 or 6cy7, the
volume range for normal listening is reduced to 7 o'clock position to 9 o'clock
for my senn hp. and 8 o'clock to 11 o'clock for the denon d5000.
these output tubes do give a faint hiss noise after 12 o'clock position on the
wa6SE (with the senns) but no noise that i can detect on the highly modified
wa6. this is with a relatively high output voltage from my source of 2.25vrms.

for the wa6SE users, i think using the low impedance jack is recommended
with these output tubes; it'll lower the hissing past noon position, which is
too loud for normal listening anyway, imo (it's louder than a rock concert venue).

these amps sound so good after a 2hr. warm up period with these output
tubes. the rca sounds thicker and lusher in the mids, whereas the sylvania
and raytheons sound more neutral and thin, generally speaking.

with some socket adapters i think i can make use of 4 or 5 other output
duo-triode tubes that have similar electronics but differently arranged
pin-outs. will work on these in the upcoming months.



Thanks for the confirmation. I'm glad it is not just me. I find that 7-8 o'clock is plenty loud enough with these 6fd7 tubes. 12 o'clock would be ear-splitting
gs1000.gif
 
Jan 6, 2009 at 8:43 PM Post #285 of 508
I did not like either the GE fat 6FD7 tubes nor the slim RCA 6FD7 tubes in my maxxed wa6se.

To my ears, the fat GE 6EW7 were far sweeter sounding through my K701 cans and made far better use of the volume range of the Dact attenuator.

Simply put, the 6FD7 tubes had far too much gain for the K701s and things started to get pretty loud by the third "click" of the volume dial.

Also found the slim RCA 6FD7s (although fairly sweet sounding) to be totally lacking in dynamics. Not yet tried the fat RCA varients which arrived yesterday morning.

The supplied GE 6EW7 and ECG Philips 5R4GYB rectifier (anyone else got one of these?) seem to synergise with the k701 cans perfectly through the low impendance jack on the 6se.

I am just wondering is upgrading the rectifier to an expensive Sophia Princess or EML is likely to provide an increase in performance, especially as there does not seem to be much info available on the ECG Philips 5R4GYB?

Seems like quite a good tube and is better sounding than the Sylvania 5R4GYB tube I brought off Ebay.

Many thanks

k701smile.gif
 

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