embarking on a (epic) single driver valve amp journey

[suri]

After reading stevieboy's passionate redux regarding the attractions of a single-driver and valve amp system, I have decided to plunge like a hippopotamus into those waters(and will name them "Witches of Ecstasy!")

being a diy, i do not want to buy the loudspeaker, but will buy the valve amplifier.

i will not go with published (and tested) designs for the drivers, i will boldly tread where angels fear to soil their reeboks, so i will probably fail. - so the drivers should not be too expensive, but they should be good - will these fit the bill-
http://www.commonsenseaudio.com/an8alnicospecs.jpg

and the valve amplifier - is this good?-

Fountek Altitude 3500 Tube Amplifier - 32 Watt from Madisound

this amp is available (Thai) for $ 900.

if i fail miserably, then i could always use a proven design.

forum members, please pitch in and advise

 

[thevortex]

Well, Suri - wish you all the best. I am also looking to see if valves and me make a good pair.

By the way, where is this passionate redux by Stevieboy that you speak of? Maybe I can also read and glean information out of it.

 

[jai1611]

My knowledge on this sort of thing is limited but to me the impedance curve on that driver looks nasty although the frequency response curve is agreeably flat. Also, the sensitivity seems low for a full ranger. To me, the driver seems more suitable for use with a higher powered amp and wouldnt really work with a low powered single ended tube amp (1.5-3w type). Search around for some user builds to see what kind of applications work with the drivers. In the under $150 budget, also consider the Fostex 6 inch or 4 inch options if importing.

No idea about the amp. The wattage suggests that this amp might well be happy with regular 2/3 way speakers as well.

p.s. I recently put together a Fostex 167E based bookshelf that I've paired with a miniwatt

 

[suri]

By the way, where is this passionate redux by Stevieboy that you speak of? Maybe I can also read and glean information out of it.

here it is

=this is a popular opinion on many forums online and in articles i've read over the years. those with single drivers and SET amps tend to settle down with them while those with multi-driver, bass augmented systems tend to keep upgrading components, searching for that perfect system that will give them happiness, that extra treble that extra iota of bass. the point is not that they're wrong, i'm sure they derive great happiness from upgrades but a single driver and SET amp tends to be more emotionally satisfying and a more 'final' system, all its shortcomings notwithstanding. i will maintain an open mind and will pm you if i ever come down that side for a listen but i really doubt i'll hear the emotion and soul i hear compared to what i've got now.

 

[suprateep]

way to go suri - keep the forum burning with the build and test reports man. Someday even I might join the DIY brigade :clapping:

 

[santhosh]

Wow Suri, all the best mate . Keep us posted on how you go.

 

[grubyhalo]

Good luck! Will be subscribing to this thread...

 

[stevieboy]

and the valve amplifier - is this good?-

Fountek Altitude 3500 Tube Amplifier - 32 Watt from Madisound

grin, didn't know i'd have that effect on you! good luck! but you might as well do it right.

if you want the best of a single driver, get a good fostex driver like george has done. its the same driver that my speaker has. that project is a good one to explore.

the other part is the tube amp. el34s and a push pull (looked like it) are way way off the mark as far as my opinion goes. choose a direct heated triode. you'd need to research tube qualities before choosing the amp. most people assume ok lets get into tubes and then jump into the first tube amp that seems to reviewed well. and then they're surprised they dont like the sound. more than SET or push pull, the tube itself makes the biggest difference in sound. so please please please start at the right point - the tube

popular choices for SET amps are: 845, 2A3, 45, 300B. the 845 is powerful and big sounding, the 2A3 delicate sounding and intimate, the 45 is very honest and extremely 'there', the 300B is a lush sounding tube that does bass not as well as an 845, a 2A3 or a 45. so as example if you get a 300B SET amp and complain about bass that's not tight you quite obviously have not done your requisite homework! you have SET amps based on other tubes like the el34 but that's taking something that's not right for the task and trying to force it to do something it was not intended to do.

my suggestion suri, get the 2A3 amp from viren and experiment with a 45 tube bought off ebay. that ought to give you a true taste of single driver SET sound.

liking it is another matter altogether and depends on how well you've done your homework on reading up on the qualities of the combo and what is required, being comfortable with giving up certain qualities in order to gain certain ones. judging by your amp choice, you haven't quite done your homework yet so be prepared to be disappointed

regards

 

[thevortex]

Stevieboy - is there a particular web link that you would suggest to help me learn more about each distinct tube's characteristics and in general learn more about tubes and their place in valve amplifiers? Thanks in advance.

 

[suprateep]

p.s. I recently put together a Fostex 167E based bookshelf that I've paired with a miniwatt

so how is the combination holding up?

 

[unleash_me]

Hope this helps.

Tube Amp FAQ 1/20/99 (Frames supported)

Justin Holton's Vacuum Tube / Valve Amp FAQ

Vintage Amp Tube Charts

Happy reading!

 

[keith_correa]

After reading stevieboy's passionate redux regarding the attractions of a single-driver and valve amp system, I have decided to plunge like a hippopotamus into those waters(and will name them "Witches of Ecstasy!")

being a diy, i do not want to buy the loudspeaker, but will buy the valve amplifier.

i will not go with published (and tested) designs for the drivers, i will boldly tread where angels fear to soil their reeboks, so i will probably fail. - so the drivers should not be too expensive, but they should be good - will these fit the bill-
http://www.commonsenseaudio.com/an8alnicospecs.jpg

and the valve amplifier - is this good?-

Fountek Altitude 3500 Tube Amplifier - 32 Watt from Madisound

this amp is available (Thai) for $ 900.

if i fail miserably, then i could always use a proven design.

forum members, please pitch in and advise

IMO, you can't go wrong with DECWARE amps. They are relatively cheap too. Sound is BRILLIANT. I heard these for just 5 minutes in a tiny shop - couldn't see what speakers they were paired with - The amp. stuck with me because I specifically asked the guy at the counter what amp. he was playing. I had a train to catch so I had to rush. The next time I visited [after a year] the shop was gone.
I checked the DECWARE site - they have the SE84C which is the cheapest and I heard the SE84B [I think - and I'm 99% sure the shop guy said a B and not an A or a C]. They also have DIY kits for that amp. if you are so inclined.

 

[stevieboy]

Stevieboy - is there a particular web link that you would suggest to help me learn more about each distinct tube's characteristics and in general learn more about tubes and their place in valve amplifiers? Thanks in advance.

hi vortex,

https://www.tubeworld.com/12ax7.htm
12AX7 Tubes in Stock
Audiophile
AudiogoN ForSale : Accessories: Tubes
Upscale Audio - Rare Tubes
Tube Classics
tubemongerlib.com

however, you can't go wrong with a little common sense logic

stick with one tube type for a week or two. google it, google it with 'amp' attached. you'll get plenty of reviews of that particular tube used in different types of amp designs and different reviewers opinions of the sound of the particular tube. most net reviews start with a general sound of the tube/amp maker before going on to review the amp in question so that's a good way of gaining knowledge.

have fun!

regards

 

[keith_correa]

p.s. I recently put together a Fostex 167E based bookshelf that I've paired with a miniwatt

Can you share build details for your 167E based enclosures? Sound [no pun intended] impressions?

 

[thevortex]

Thats a lot of homework - Stevie and Unleash_me! But all in good cause, I hope.

Let me get through that and see if it clears up my haze a little. Thanks a bunch both of you.

 

[jai1611]

so how is the combination holding up?

Can you share build details for your 167E based enclosures? Sound [no pun intended] impressions?

the plans can be seen here: http://www.fostexinternational.com/docs/speaker_comp/pdf/recom_enclose/167e_enclrev.pdf . I used MDF with cotton for damping.

I've tried the speakers with a T-amp, the miniwatt and a couple of solid state amps. Overall, the speakers seem to have better transparency than any bookshelves I've heard under the 20-25k mark (the ones which seem to come close are the Quads). The bass is weak but ok for a small room (this is something I expected). The midrange is clear and lends a sense of presense (the singer is in front of you when you close your eyes). The treble is very slightly rolled off but not really a problem. The soundstage is very good and the speakers tend to disappear. Overall, the only bookshelf I've heard in the sub 50k segment that I would take over them is the Dynaudio Audience 52 (which I have in my main system).

I still havent made up my mind about the miniwatt. Dont think its fully burnt in yet (less than 50 hrs, the speakers have done over 100 hrs). Power is genuinely an issue with this amp. Even with these bookshelves, I often end up with the volume at 12'o clock. The source is a Nad C515BEE. I want to try the t-amp with a better power supply before deciding which of the two suits the speakers better. I also want to try the speakers with my Marantz PM6000 OSE, which is currently away for service.

 

[keith_correa]

the plans can be seen here: http://www.fostexinternational.com/docs/speaker_comp/pdf/recom_enclose/167e_enclrev.pdf . I used MDF with cotton for damping.

I've tried the speakers with a T-amp, the miniwatt and a couple of solid state amps. Overall, the speakers seem to have better transparency than any bookshelves I've heard under the 20-25k mark (the ones which seem to come close are the Quads). The bass is weak but ok for a small room (this is something I expected). The midrange is clear and lends a sense of presense (the singer is in front of you when you close your eyes). The treble is very slightly rolled off but not really a problem. The soundstage is very good and the speakers tend to disappear. Overall, the only bookshelf I've heard in the sub 50k segment that I would take over them is the Dynaudio Audience 52 (which I have in my main system).

I still havent made up my mind about the miniwatt. Dont think its fully burnt in yet (less than 50 hrs, the speakers have done over 100 hrs). Power is genuinely an issue with this amp. Even with these bookshelves, I often end up with the volume at 12'o clock. The source is a Nad C515BEE. I want to try the t-amp with a better power supply before deciding which of the two suits the speakers better. I also want to try the speakers with my Marantz PM6000 OSE, which is currently away for service.

About the miniwatt [and the like] and power - see this

 

[jai1611]

About the miniwatt [and the like] and power - see this

Some of the concepts look familiar.

The miniwatt seems to have 1.5w of usable power and the t-amp around 5w. Possibly the 1.5w would be enough with a more efficient, tower based on the same fostex driver or even a less damped version of the bookshelf. The 5w of the t-amp seems sufficient for my bookshelf though.

 

[gobble]

Some of the concepts look familiar.

The miniwatt seems to have 1.5w of usable power and the t-amp around 5w. Possibly the 1.5w would be enough with a more efficient, tower based on the same fostex driver or even a less damped version of the bookshelf. The 5w of the t-amp seems sufficient for my bookshelf though.

I'm curious - why is less damping critical for low wattage amp?

TIA
regards

 

[jai1611]

I'm curious - why is less damping critical for low wattage amp?

TIA
regards

I've used fibre stuffing for damping. I suspect this reduces the effective efficiency of the speaker. Not sure though