Foray onto valve amplification

Smoothjazz

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Good morning members
The happiest and most successful 2022 to you.

I want to foray into valve amplification this year and am looking for some advice as my knowledge in this area of audio is very little. I have done some reading/research and the Mingda brand appears to be very highly rated based on performance/price/build.

My main speakers are  Monitor Audio PL200 and I listen to music at very moderate levels so outright power is not what I am after, Would something like the Mingda MC3008-AB be a match?. I am not stuck on Mingda as a brand so advice on other brands would also be welcome.

 

AlleyCat

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For just on R70k new spend,there should be a decent number of offerings new and second hand judging by the recent Pathos Logos MK II sale for just over R30k, for example.

I would ask to home test any offerings ( preferably over a number of days) and then decide.
 

stereosane

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Pathos is a hybrid so not strictly a tube amp, are you wanting a pure tube amp or are hybrids included?

Ming Da and Cayin get great reviews. Id look at the Cayin CS55a, you have the choice of going with El34 or Kt88 tubes plus it can flip between Triode and Ultra Linear, I think you'll be very happy, I've akways had a strong feel that MA speakers will sound there best on a good tube amp.

 

fredeb

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If you intend driving the PL200's I would advise getting a Push-Pull , not Single-Ended amplifier . There are also Push-Pull 300B amps out there .

These guys do free shipping ( they have obviously calculated shipping into the price )

https://shenzhenaudio.com/products/yaqin-ms-850-300b-three-pole-class-a-high-fidelity-electronic-hifi-tube-power-amplifier

You may need to buy another quad of higher quality 300B's , not cheap , something worth considering when buying 300B amplifiers . One 300B max dissipation is 40W , which certainly doesn't mean it will put out 40W audio watts , and if it does dissipate 40W of heat it won't last long . So definitely don't take the 40W to mean audio output power . In Single-Ended configuration it will probably put out 10-12W . If you do intend using this amp I would suggest you buy or build or have built a pair of high efficiency horn loaded speakers .

I can also suggest that you start lower down the spending ladder with a EL34 , 6L6 , or KT88 Push-Pull amplifier , you can always sell the amp and try something different as you learn more . Buy a 2nd hand amp , play with tube rolling , and first learn about what you are dealing with .

Karel Mars [member=817]Mars[/member] also has been building valve amplifiers here in SA for many years , and though his designs may not be as "Bling" as other examples , they may well out-perform them .

https://www.marsamps.co.za/stereos/

Karel will also build amps according to your needs . That is : Do you want an integrated amplifier ? Do you want a power amplifier and separate preamplifier ? Do you need a phonostage ?







 

Smoothjazz

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Thank you to all those who responded with suggestions and thoughts.

I am definitely looking at pure tube only. On bench test reviews the MA's efficiency is rated between 86 and 88db, somewhat lower than the the quoted 90db - i think the push/pull configuration would be the best?

I have sent Audio Exchange an email about some advice om Mingda - awaiting a response from them.

 

Air

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Hi Smoothjazz,
I did a quick look at what is available on the net in terms of measurements for your speaker and what is important is to note is that it is not only the sensitivity that needs to be considered when looking at amplification but also the impedance and electrical phase angles. It is clear you need a beefy amp for the MA PL200.

Monitor Audio Platinum PL200 loudspeaker Measurements


Sidebar 3: Measurements
I performed the quasi-anechoic measurements of the Monitor Audio Platinum PL200 with DRA Labs' MLSSA system and a calibrated DPA 4006 microphone. The grille was left off for the measurements, as that was how Bob Deutsch auditioned the speakers. The Platinum PL200's sensitivity is specified as a usefully high 90dB/2.83V/m; my estimate was actually a little higher, at 90.4dB(B)/2.83V/m, though this is within experimental error of the specification. This speaker will play loud when driven by amplifiers of low or moderate power. However, its electrical impedance (fig.1) does drop below 6 ohms in the lower midrange and mid-treble, with a minimum value of 3.6 ohms at 150Hz. The amplifier used should be 4 ohm-rated.

So I am in agreement with [member=15006]stereosane[/member] views and even would go further to say that 6550/KT88/KT90/KT120/KT150 push-pull amps would be the only ones really suited to your speakers.
 

Smoothjazz

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Thanks Air

This is very comprehensive, thanks for taking the time to research this. Push/Pull appears to be the answer. Once i have some options narrowed, i will seek some more guidance
 

gavinbirss

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fredeb said:
Good to get an amp with 4ohm and 8ohm taps .

This may exclude Manley amps so perhaps only consider those with 5ohms output transformers.
:giggle:
 

WhoIsJOB

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I would second the opinion of taking an amp from Karel [member=817]Mars[/member] - I would even suggest doing the build with him as you learn so much from the whole process.
He has some great higher end options and all the knowledge to go along with it.
I recently completed a KT88 build with him and it was worth every cent.

https://www.avforums.co.za/index.php/topic,97862.0.html
 
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