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What's the ideal tube amplifier for me for max. $660 , maybe a kit ?

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Hello !

Since I got an 1960 Philips AG9016 (2x2W, EL95 SE) I am into tubes ! I read this forum and found the people here talking very friendly compared to other forums.
Now I would like to buy a modern good sounding tube amp for absolute max. 550 Euro (ca. $660) incl. shipping. A kit would be nice to try ! (although this is a DIY forum, I want to start with a kit instead all custom made)

My situation: I have a room of 7mx3,5m and a pair of "PROTON" "HP-400", 2way bassreflex, 80x26x25cm, 19cm bass chassis, tweeter is coupled with simple RLC crossover with 2,2 Ohm and 3,3uF, bass is directly coupled. I think it sounds quite good, It gets reasonably loud, although not enough in every case, with the 2W from the Philips. Sadly, I don't know efficieny and impendance curve. Can someone estimate the efficiency of my speakers from these data ?

The amplifier:

It should not be a monobloc, I don't like them. It has to have a volume pot, not using a pre-amplifier. One source (CD-Player) would be enough. It should be new, unused. If a kit, it should be complete regarding mechanical construction and included parts.

The sound:

I would like to hear emotions, hear the echos and sustains in the recordings, every instrument and especially voices naturally. It should sound "lively". When singing duets, one should hear both voices separately, as it does my 1960 Philips. (Not so my AMC 3020 solid state !) The bass should be deep and solid, but not too strong, but a little less boomy as with the Philips. It should sound different to my AMC, should play with more passion. The only things I don't really need is much power, "slam" and High-End "correctness", detail and definition. I'm not willing to play loud (I have neighbours !)

After intensive surfing around the web I found these products:

SE:

*) Norh "SE9", SE P, 2xECC83, 2xEL34, 9W, choke ?, PCB, ca. 330 Euro incl. shipping
*) ASV Sebart "STA-8", SE UL, 2xECC83, 2xEL34, 8W, choke, air wiring, 530 Euro incl. shipping
*) HB Ampdesign "EL34 SE", SE P, PCB, 450 Euro without case, tubes and shipping
*) Gabe "CGV-0606",SE UL, 6SL7, 6L6, 6W, air wiring, choke, volume pot ??, ca. 461 Euro without shipping (how about tax for Austria ?)

PP:

*) Audio Institute "VR70E", 2x6F2, 4xEL34, 30W, 415 Euro all incl.
*) Opera Audio "Ella Consonance", 4xEl34, 40W, ca. 500 Euro all incl.
*) ASV Sebart "KSTA-50PP", 4xEL34, 30W, 530 Euro inkl. Versand
*) Jolida "102b" 2xECC83, 2XEL84, PP UL, 15W, ca. 584 Euro without shipping
*) Rheinhöfer "SV86PP", 4x PCL86, PP UL, 450 Euro without shipping
*) World Audio Design "KEL84", 2xECC83, 2xEL84, UL, PCB, 15W, ca. 423 Euro without shipping
*) Gabe "MAG-1515i", 4x6EU7, 4xEl84, 15W, ca. 461 Euro
*) Stoetkit "Junior", UL, 4xECL82, PCB, 9W, 495 Euro

No options:

*) Aurexx "Crystal Clear 1", 2xECC83, 2xEL84, 3W, ca. 300 Euro --> too less wattage
*) Raphael "TSE4", 2xEcc83, 2xEL84, SET, 2W, 430 Euro without shipping --> too less wattage
*) Decware Zen, 2W, ca. 450 Euro --> too less wattage, bad looks, volume pot on backside !
*) Bottlehead Paramour, ca. 420 Euro --> No 230V !, Monoblock, no volume pot !
*) ASL Wave 8 ca. $99 --> Monoblock, no volume pot
*) Antique Sound USA K2003 ca. 330 Euro --> no more available !
*) Joplin Consonance ca. 600 Euro --> too pricey, tube changing too expensive

I really don't yet know if SE or PP is my thing or if one can really categorize the sound by this. I only can say that I heard the Vellemann "K4040" PP with 8x EL34 and I didn't like the midrange compared to my Philips. It sounded like my solid state.

Can you help me getting further ?
Any other products I didn't mention ?
How much Watt would I need ?

Many thanks and looking forward to an interesting discussion,

Günther (from Vienna)
 
Hello Gunther,

That is an extensive list!
I have heard only the Stoetkit play and that little thing is magic. It has a 'magic-mushroomfactor' that draws you into the music to an extent no even my reference triode system does (or any other amp that I heard sofar). This cute little amp surprised me time and again.
Power can still be a little limited on regular 90dB speakers. Anyway its only 6dB up in powerlevel compared to the AG9016.

If you want to go ultra on clear vocals, tunefull bass etc. you shoud save for a real DHT 2A3 (sun) amp for instance and make some higher efficiency loudspeakers (i.e. fostex voight pipe). You will be amazed!

regards, Coen
 
Hello Günther,

Wow! I am touched that I am on your list at all, let alone on both SE and PP.

What I can say about that sound of my amps is read the testimonies from my customers. I also have a couple of not as good customer replies I am going to put there, because one cannot please everyone.

The comment I got about the MAG-1515 from one customer is that it is not quite as warm as his other amp (I forget off hand what it was). No, my MAG-1515 does not sound like a conventional tube amp. Voice sounds natural, not enhanced like a typical tube amp. Bass is deep and tight, not muddy or boomy. He wanted more of that fat sound.

The other was a comment about the CGV-0606. The customer said it sounded solid state. However, it had not broken in yet, and he was having power problems as well as a HAM operator (amateur radio transmitter) living nearby which induced interference. He later admitted that when he cleaned the power (AC filters) and listened when the HAM was not transmitting, the sound was better. That plus the amp was not yet broken in.

All I can say about it from my perspective is that all my amps sound about the same as each other, from SE to PP to 300B. And yes, I can customize if you desire (add a potentiometer). As for tax... I believe you pay that when you receive the unit. I do not know off hand what my responsibility is for that. I do know that anything I sell ouf of this state is not taxed in this coutry. To Canada, they pay tax to Canada based on the value of the item shipped from the US (or any other country).

Just about all good tube amps will sound good at low volume as well as high volume without changing their sonic signature.

I had the pleasure of building the Bottlehead for a customer. Simple circuit to put together. Sound is very good. Solid and natural. My only complaint is the chassis. Flimsy and not covered. That is, there is no bottom cover (not very safety conscious). It used a very thin aluminum chassis. Otherwise, it is pretty. Nice wood base. High quality components.

The Decware ZEN I would imagine is a very good amp also. I have made Steve's woofer encolsures. If he can make a cabinet make magic like the death box, I can only imagine how nice his ZEN amp sounds. You would be surprised how much 2 watts of tube power really is. If you want to you can connect the output tube as a pentode and get more power. Steve Deckert is a wizard!

Hope this helps without being too self promoting.

Gabe
 
What is the best option...

Hello Co& et alter,

I'm rather surprised that the Stoetkit Junior sounds so good, because it's the same configuration (PP ECL82) like the Wave 8 and the Wave 8 are not really sounding good.
I heard the ASL Wave 8 and the ASL MG-SI15, at my home, with my speakers. The MGISI15 has a, tough very detailed, very coloured sound and doesn't have a flat frequency response with my speakers. The Wave 8 sound warm, but quite gritty (distorted).
The AG9016 pleases me very, and I got good comments on it. So I modified it further to improve it. I added one new elko to power supply. This improved "punsh" and dynamics. I removed the first stage (bass and trebel), this improved the frequency response on both ends but the pleasant sound remained. But now I have too much bass at 50HZ and 60HZ . I removed the coupling capacitor at the preamplifier stage. Now, strange !, I have too less bass (shouldn't it be quite the same ?). Somehow also the sound "dried" a little out .Also, I removed the cap (HF blocking ?) on the output trafo, this openes up the highs. The sound is very musical now. The only problem is still a boomy bass. I measure 0,6 Ohm resistance at the OT, 0,7 Ohm at the LS connector and 0,8 Ohm at the end of the cable. WIth my speakers connected , I measure 0,7 Ohm. How good/bad is the damping factor of the Philips ? How can it be calculated ?
Can someone tell me what is excatly the capacitor in the NFB branch for ?
Next will be replacing some of the capacitors !
I know that I won't solve the bass problem, so I want to buy a new tube amplifier, with better damping factor, which should sound similar to the Philips. I would like to stick to SE. 2 Watt is enough for me, I can play loud undistorted levels now.

Günther
 
Hello Gunther,

The NFB helps lowering the output impedance. How much depends on the amount of feedback and the stage the feedback is tapped from (from output tube or OPT secondary). I do not have a schematic of the AG9016, but I guess with two ECC83 in series it will be about 10-20 times. Anyway the demping factor should be quite low (>1). What you need to consider is the influence of the OPT: in my experice transformers with limited LF response sound more bassy than the ones who don't, yet the used coupling and PS capacitors also have an even major impact. Also circuits with NFB or HF oscillations can sound a little boomy...

The capacitor in the feedback circuit is to prevent oscillations (= stability). Usually for high frequencies the phase is shifted at the circuits output as result of parasitic capacitances in the circuit (i.e. tbe-miller capacitance or intercomponent capacitance). The NFB-capacitor shifts these frequencies 'back' so to speak and prevents a positive feedbacksignal wich leads to an even more increased signal at the output of the circuit (and so on!!!). Do not remove it and check its value!

In the OPT there is also parasitic capacitance and inductance. These two form a resonating circuit at high frequncies, and if not well damped in the OPT itself need be supressed. That is what the capacitor on the OPT is for. The HF oscillations can of course help a speaker sound more fresh and alive. Please note that these can appear at the NFB point if the NFB is tapped from the OPT seconday! If the OPT resonance is lower in freq than the 'workingpoint' of the NFBcapacitor you're in technical trouble! (it may thus very well be a part of the NFB concept!!)

I did not hear the stoetkit on your speakers of course, yet did not find it to be rough or coarse soundwise on regular speakers. Just very 'musical'. Maybe it is because fo the high quality Stoettransformers. El84 have usually a more romantic kind of sound though.

regards, Coen
 
Hi Günther,

from your extensive list I have only heard the Decware zen amp, and I can tell you that it's an awesome little amp. I would consider them quite neutral, very very reveiling and clean. With a little bit of tweaking they sound really good, but won't of course drive your speakers to "disco" levels.

El84 have usually a more romantic kind of sound though.

I cannot second that... My current amp is a heavily tweaked (by Steinmusic in Germany) Leak TL20, and what I'm hearing is very neutral and far from being romantic. In stock condition I don't know, though...

Servus,
Oliver
 
Gunther,

I would suggest getting a MingDa MC34B. This is a 20 watt/ch integrated with two selectable inputs and volume control. Uses P-P UL 6L6's. I have one and have *upgraded* it by installing a set of old Mullard EL34's. This amp won hands down with the stock Chinese 6p3p (6L6 equivalent) output tubes installed, when tested against several other more expensive tube amplifiers in my own listening tests.

IMO this sweetheart amplifier cannot be beat for value and the performance can match amplifiers costing many times more. I am not using it because it is inexpensive, I am using it because it is one of the best sounding tube amplifiers in my home. It is also the quietest.

I can be of assistance in you getting one if you want my help. Send PM.
 

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