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SE 300B or PP KT88 amps?

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#22
The Ming Da stuff is what I would LIKE to pick up when I'm there

Usually too big, to expensive and too heavy... SO I dont get them to plug it in and listen...

I believe they've been getting a reputation though - If the guy in China has the nerve to ask for 500 or 600 quid they know they're sat on a good thing

If it was me I'd also think about the opera consonance too. I think these are from DIY hi-fi supply (http://www.diyhifisupply.com/) They of Ella fame, again well reviewed I belive but not heard in person..

Sorry, but I tend to go for things that'll fit in a suitcase :cannotbe:

As usual - advice if you feel like skipping a local distributor is be careful - there are great deals on ebay but...

Andy
 
#25
I would think this one with 805 driven by 300B is very interesting

http://www.ornec.com/product/EU/Meixing_MingDa_MC3008-AB_tube_integrated_amplifier/

But it gets VERY hot and are transformers any good at this level, relative expencive tubes


Just to have a nice and easy tubeamp I could choose this Cain

http://www.ornec.com/product/EU/Cayin_Spark_A-50T_Tube_Amplifer/

Its a brand new model with softstart


If all prices are with tubes I wonder if there could be an issue with the tube quality

edit, but please, I am no expert at all :bawling:
 
#27
arvin said:
I am interested in this beast:
Click to expand...

so am I! - you would...

All Meixing Mingda kit I've seen has been thoroughly professional UK standard even... :bigeyes: I want one too...

EL34's are IMHO very underrated vs the KT88, Ok they have a normal bottle but in a lot of ways they can surpass it inspite of their lower power dissipation. The pictuires show JJ EL34's - a tube I'm currently very fond of

Heck I have a 1/2 built KT88 amp and I checked the shipping 🙂 IF only I could use another amp... Love that separate power supply

Andy

edit : 791€ :hot:
 
#28
navin said:
The Cayin MT35 on ornec seems another option.
BTW what tubes are used in the Cayin A50T or Opera A100III?
Any opinions on the Yardland seres of amps found on ornec? esp the 34C or 34B?
Click to expand...


FV34Ciii = excellent, (this one http://www.yarland.com/FV-34C.htm)

but there were two faults

1) transformers are warm in UK "heat" - its a tiny amp
2) no triode mode which I belive the EL84's are really good in

- I would recommend, I enjoyed mine

incidentally the tiny little input valves, although being quite rare are well chosen - a sign that some thought went into the design if you ask me..

Andy
 
#29
tinitus said:
I would think this one with 805 driven by 300B is very interesting

http://www.ornec.com/product/EU/Meixing_MingDa_MC3008-AB_tube_integrated_amplifier/

But it gets VERY hot and are transformers any good at this level, relative expencive tubes


Just to have a nice and easy tubeamp I could choose this Cain

http://www.ornec.com/product/EU/Cayin_Spark_A-50T_Tube_Amplifer/

Its a brand new model with softstart


If all prices are with tubes I wonder if there could be an issue with the tube quality

edit, but please, I am no expert at all :bawling:
Click to expand...


'at this level' you wont get Sowter OPT's of course but they do seem pretty darn good EXCEPT for the 'poor' SE amp I got. Even that responded to a bit of a tweak. Especially after the advice I got from this 'ere forum...

My experience with Chinese tube quality is OK - dont worry about it. (You can get an EH octet in China for 1200 RMB imagine you are a manufacturer of amps)

Standing advice with Chinese amps however, is "Check it yourself if you are competant", they will be entirely handbuilt - errors happen and one wrong bias resistor... I've said this before and I don't mean to diss the chinese - 99.999% is totally fine

Andy
 
#32
Arvin

Best sounding tube...hard to answer
There is more than one tube in most amps
Also design matters... and parts used
And setup can influence tube life, and sound quality
For a newbie reliability and maintenance are important
Further more I think that very special and "tricky" or hard to get tubes are only fore hardcore enthusiasts
there is very little information following theese amps

To be certain my choise would still be Cain A50T
But with such many interesting designs from MingDa I would expect them to know what they are doing
At first glace they may look like empty "showcases", which is apparently not so...300B driving 805 ...weird
its like poker, you may winn bigtime

In the end it may come down to habbits and which speakers you have, and your taste in music, and how powerfull you like it to be


edit, ups, price on the 34AB you like has suddenly gone up a bit🙄
 
#33
tinitus said:
Arvin

Best sounding tube...hard to answer
Click to expand...

Yup, hence the fun in tube rolling. somewhere on here theres another thread about the "best production EL34" Also bear in mind that Power pentodes can be conected in at least 3 different ways [pentode u/l or triode plus the various configurations :cannotbe: )

To TRY and shed some light though - The 300B was/is an audio triode, the curves are very linear and being a triode the distortion is supposed to be realtively benign. (but you can make Pentodes into Triodes too) Big diadvantage is the directly heated nature of the cathode = Hummmmmmmmm

In practice a P-P EL34 or KT88 amp will / ought to get you more for your money. Plus that MC34AB means you'll not need to heat the room 😉

BUT....

If I read the datasheet for the 845 correctly, it like a BIGGER 300B ie another DHT, albeit not one designed specifically for audio. the problem with using a 300B to drive it is you now have a selection of reasonably expensive tubes (Question - why not just dual 300B's? to quote, "weird")

The 845 looks pretty linear though (upto -300v grid volts!) one other consideration here, outside of cost of tubes is that the 845 is probably biased at over 750v at the plate. :hot:
Ask yourself if you are happy with that? :att'n: transformer insulation has to withstand up to 1500v - and if you do start to tweak its not likely you'll get a second chance... :dead:

Andy
 
#34
Andrew, I have to correct you on one point

Its a 805 driven by 300B, not 845 - but they should be similar

Althoug a PushPull 300B driven by 300B would give same watts, the 300B driven 805 is still SE(single ended), not the same thing

BUT, you are absolutely right with the high voltage, it may only be for hard core enthusiasts, but interesting amp

But with the seperate supply on that monster 34AB, I am not sure about that, if its completely safe and sound, with those connections


I agree with you, a PP EL34 or KT88, two tubes ea channel, if thats what you say - it can play really nice and with enough power - but be carefull, some of the amps may use more expencive hard to get driver tubes

In China it goes relly fast, day by day, and some of the design are modified in the latest design, and I believe that some of the "new" are really not the latest
 
#37
Just a small point:

On my data sheets the EL34 is rated as 25W plate dissipation, while the KT88 is 35W (some firms rate it at 40W). It is thus really capable of higher output, not simply mutually interchangeble. I myself also have some misgivings in considering pentodes and beam tubes as exchangeable, but distortion graphs show little difference, so perhaps just a personal preference.

Regards
 
#38
hi navin,

do U only considerate use KT88 or El34 PP amps??

Do U like diy for them. there will had one tube under rate series & had very good sound. EL509/519 or cheaper EL504/500 PP tube amp. There had more choice in ebay, famous brand of them. I agree that EL34 & KT88/6550 tubes was very good sound. But in my test in triode connect el504 was very good. I use el504 triode connect & cathode output with interstage push 211 tube. input stage was C3M triode connection. If I use El504 plate out with 1:1 interstage. can push 845. hope this information I can help.


this mis my 845/211 tube amp top view.

thx

thomas



An externally hosted image should be here but it was not working when we last tested it.
 
#39
tube-lover said:

do U only considerate use KT88 or El34 PP amps??
Click to expand...


Not really. My speakers are about 86-87db/1W and hence I figured I would need about 30W/ch (to reach 100-101db) and was looking for amps that would require less than 500V not that 500V is any safer than 1KV but psychologially atleast it felt safer.

I started out thinking about a EL84 PPP (parallel push pull) but was convinced (by people more experienced than myself) that maintaining bias on 4 tubes would not be easy and that I should consider PP not PPP. Considering availabity of advice, circuits and parts, the obvious choice was EL34. However since many splitter-driver tubes (6SL7- 6SN7) can drive EL34/KT88/6550/KT66 I started looking at circuits where the output tubes can be interchanged (a la Ella Consonance) and where I could hear these changes for myself.

Many moons back a very nice guy called Wayne (on diyaudio) effectively designed a nice tube amp for me. See the "EL34 schematic confusion" thread.
 
#40
hi navin,


I don'y know how about your budget.

If U limit the budget I suggest U choose EL509 PP.

HV will around 350V only. All parts will not expensive.

Many tube such as telefunken, simens or philips different brand U can choose.

If U choose EL34. U will not easy to change different type of EL34 turning the sound.

KT66 will be the same too.


I will not mention the driver & input stage of the PP amp.

But I thought E180CC/5965 ( mid-u) tubes with high current will be one of good choice of spitting tubes. not expensive for NOS tubes. THis tube will be funture star in tube word.


BTW, if your budget is enough, pls considerate emission lab 520-V3.

Approx 500~600V. max 200ma current had 23~27W SE power output. U can considerate my circuit ( EL504 cathode follower with IT driver with this tube). very good dynamic with pure triode sound. since this tube only had 470ohm plate resistance. OPT need 30watts, 200~250ma 2~2.2K will enough, lower impendance OPT will easy to get good band width.

This tube transconductance (Gm) 8,5mA/V , for small signal will very good.

http://www.emissionlabs.com/japan/datasheets/EML520B-V3.htm

thx


thomas
 
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