All things tube amp

Hi all,

lets touch on the tubes and tubeamps here. For some would call it valve amps.

Whether its 6V6, EL34, 5881, KT88, 6550, 2A3 ro 300B or 845, let's share some experience to it. What is your aim in mind, do u want your tube amp to sound like the McIntosh, is that a destiny?

some said the EL34 is good for classical and jazz while the KT88 is good for vocal. is it true 300B is the ultimate women vocal reproduction ?

Hi
I am also pretty new to tubes ... just starting out too.

I run a Jolida 302 which runs the EL34. The mids and vocals are what stands out to me. I like them very much

I also audition the Jolida 502 (if i remember the model correctly), they run on KT88. For my taste, I find that this model packs a lot more punch and power, but loses some of the warmth compared to the EL34. In a way ... i find the KT88 beginning to sound "more like solid states" ... but if you need to drive a big room ...then this would probably sounds a lot better

not sure if it is just the way the jolida are built ... never had the chance to audition other tube amps ...

I would like hear some opinions about Audio note and Jadis users too.

Some of the tube transformer are special wound like the McIntosh. Also with the PCOCC being available, lots of new tube amp come with OCC wounded transformer.

In terms of EL34 vs KT88, some say EL34 should sound sweeter compared with KT88.

To me KT88s are slams with tubey warmth.

But I won't say they are like solid states.

Is there any other amp that can use either EL34 and KT88 interchangeably? So far I only found one that is Primaluna but the price will make my wife literally kill me

Some products can share the same platform with minor tweaks such as 300B and 2A3 using the SunAudio.

For some product it is one way such as 6L6 and 6V6

So far has anyone checked whether their tube amp transformer core is PCOCC and also the steel plates used is imported Z11 silicon steel ?

Amp thats interchangeable with EL34 to KT88 are generally not good nor optimum (IMHO). One have to understand tube circuitry, optimum operating perimeters and type of circuitry implemented to voice the amplifier, not to mention the quality of output tranny and other components altogether that'll dictate the performance. Different circuit implementation principles and operating of the same valve under different circuit will yield different tonal and power characteristics. It all depends. Some like penthode configured as Triode mode for better vocal performance and some prefer full penthode or tetrode power for other music genre or all rounder..personal preference here. I can't say everything in one paragraph.
Generally, if a shortlisted valve amp (based on your budget, affordability) is pleasing to your ears for long term, by all means buy it as you're the one going to live with it.

I listen to tube setup at the hifi shops and the sound is really mellow. I think part of it is the listening area which if setup properly, will yeild lots of listening pleasure.

Wonder how's is the 300B or the single ended EL34 match with the full range such as fostex or horns. must be damn sweet.

chua55 wrote:I listen to tube setup at the hifi shops and the sound is really mellow. I think part of it is the listening area which if setup properly, will yeild lots of listening pleasure.

Wonder how's is the 300B or the single ended EL34 match with the full range such as fostex or horns. must be damn sweet.

me using these...

I've never owned a valve amp but I have listened to many valve amps and one thing that always strike me that they are very good with vocals, accoustics, jazz but when it comes to pop, rock, electronics, it just doesn't gel well. I'm just curious is it just me or are there any valve amps out there that can sing all sorts of musical genre?

Go around and listen lor. The journey of discovery is worth your time spent. Along the way u may find a convergence of solid state sound with that of valve sound in some hybrid equipments.

That's the whole point of having the tube amp is it. Anyway I believed from what I read, KT88 is more suitable to those fast music. More bass slam. I just use my SS when I'm feeling a bit of Metallica.

samn wrote:I've never owned a valve amp but I have listened to many valve amps and one thing that always strike me that they are very good with vocals, accoustics, jazz but when it comes to pop, rock, electronics, it just doesn't gel well. I'm just curious is it just me or are there any valve amps out there that can sing all sorts of musical genre?

Not necessary. Some tube amp can go heavy metal. e.g. tubelab.com

He is a fan of diy and he had such vast experience with tube and amps. His mosfet drivers can tame those speakers with heavy metals..

This circuit is not common in Asia.

samn wrote:I've never owned a valve amp but I have listened to many valve amps and one thing that always strike me that they are very good with vocals, accoustics, jazz but when it comes to pop, rock, electronics, it just doesn't gel well. I'm just curious is it just me or are there any valve amps out there that can sing all sorts of musical genre?

I beg to differ on that rock and valve amps don't go well together.

I really do enjoy my Led Zeps and Pink PLoyd on my valve amp.

to me, its not about whether it can drives metal song or not, its more to tube maintenance. anyway any of you ever audition yaqin mc-100B? producing 60w/ch, its cheaper than bewitch kt88

& that bias adjustment, is it really hard to do so?

Yaqin MC-100B got good reviews all over but not my first choice because of manual bias adjustment. Might be fun for techie

The yaqin uses dual mono design, unlike the bewitch pamp. there is minimum inteference of the left and right signals.

auto bias means additional cost (often out of reach) and for some who claim 30mA is better than 40mA, they would prefer manual bias. Bias adjust is as simple as loosening a bolt with meter.

Auto bias is NOT additional cost. In fact its easier to implement in the circuitry. Fixed bias needs a negative DC supply bias (mains tranny must provide for this) and the little pots for adjustment. Auto bias is just a pair of fixed (determined value resistors) at the output tube cathode. Type of bias doesn't account for major performance. Its all the other parts and components in the circuitry that contribute to the sonic quality. Simple fact, lower bias = tubes last longer and slightly worse sound. Higher bias = tubes may run hotter and less longivity but may be better sound. This is one area you can't have the whole cake and eat it. A compromise is neccessary here. I've seen many amps that were purposely biased on the lower side for longivity and reliability. How do you like if you hear that this amp, the tubes last 6 months max. Will you buy? Of course you think not.
I have a Mullard based circuit type (10Watts PO) and its the typical auto bias not very far from the book typical type circuit. I've no compliaints with what ever drawback it may have against better circuits and the sound is as sweet as ever. The tubes (current production types) also last donkey years. My purpose is never to compete my amp against others having better ones..I just sit back and enjoy the music.
Cheers.

The auto bias can be any types from Servo circuit, CCS, Cathode bias resistor (the simplest, as lowest costs). they have been many discussion about all this bias each with its pro and cons. What each trying to do is to allow the amp to self 'heal' with some minor mismatch. With common cathode at the output tube stage, one can not determine individual current draw of each tube. however it still works best with a adjustable pot to ensure equal bias current at DC condition.

Regardless of whatever bias, there will be some drift and slight differences due to various factors of tube quality and DC stability. Match tubes are approximate within some tolerances, never spot on, although it may happen but rarely.
If you're talking about most entry to mid level tube amps, they aren't going to have CCS or more complicated servo circuitry. They'll more or less be typically book type circuits in practice and as simple as you can get. You're not going to get say 30mA bias spot on at all tubes or all at the same time. One can only adjust the bias to nearest and best achievable for given tube.

Just to share some material on all things tube amps, here is the basic article.

http://www.aikenamps.com/Biasing.html

To know further about tube amp, my best read and bread and butter would be Morgan Jones - Valve amplifiers

here is how the shuguang factory tour. note the burnt tube with a white coating.

http://www.enjoythemusic.com/china_2009/shuguang/

soon all new tubes will come from them, but printed made in somewhere else

I think so too.
What about Russian tubes then..?

that makes me wonder too. so curious..

Don't just curious. Try em out. My gamble with new production Mullard paid off since I like it. Not so well with JJ

brand new?

i do have a pair of vintage mullard & yes compare to philips miniwatt, mullard sounded better.

im referring to electro harmonix

Yeah new. That's why it's called "new production" lol

EH, Mullard, etc all new production made in Russia. I choose Mullard coz it's logo looks better lol