Valve amp speakers

[hruyter]

Hi guys

I started a thread previously, asking about the bottle heads here,
well it turns out that I have a bit of a speaker issue now that I have acquired this new amp :scratch:

I want to get the best out of it but dont want to spend pots of money
:sofa:

any suggestions what is a good range of speakers or perhaps a particular type of speaker that I should look at
perhaps a set of parameters that a speakers should meet in order to deliver the best bang for buck in terms of sound from my valve amp

The Kef Q Compact speakers I have now sound nice but bass can get a bit wooly when I play dub or other very bass heavy music.

:rave:


Regards
Hill

[lurcher]

How much space do you have. Most of the the single driver high sensitivity solutions may not meet your need for bass. But a open baffle with 15" bass unit may do if you have the space.

[wee tee cee]

I just bought a pair of tannoy mercury f3s from richer sounds for under a ton.Do bass very well,more refined treble than the kefs they replaced.Pretty large but for the money well worth a squirt.Easy to drive,I use T amps so should be fine with your tubes....

[hruyter]

Hi thanks for the replies

If it was only up to me I would make room, but I do have to co-exist with swmbo, so I will have to be careful of the size.

the tannoys looked nice at richer sounds I like oak too, it will match the furniture (bonus when selling to swmbo) and a good price too ;)

any other suggestions?

:popcorn:

[IHP]

Hi Hill,

I used to own the Proac Studio 110 @ 88db/m and a pair of Quad IIs at 15w a piece drove them beautifully. A Leak 20 with them would provide more clout more clout. So in my experience these speeks. are pretty easy load and wouldcertainly be worth a listen if at all poss. They went on ebay for just over £400, though I don't know what your budget is.

What's your amp by the way ?

[hruyter]

Hi

the amp is hand made single ended EL34 with hammond transformers.
All the tubes are CCCP military stock apart from the EL34s which are more modern Svetlana (winged logo) tubes.
here is a picture
http://theartofsound.net/forum/attachment.php?attachmentid=5180&stc=1&d=1314297067
I have to take some more soon and post in the gallery

Hill

[lurcher]

Yep, that amp will be producing at most about 8W or so. I would aim at a minimum of 94dB/W. If you want to get extended bass out of it I would think 98dB/W would be better as SET(P) will saturate the output TX core at LF.

Or you could go with active bass.

[John]

I agree with Lurcher go Open Baffle if you have the space lots of drivers that will work well with that set up. add a decent bass driver and go active in the bass. Sound per pound nothing comes close Hawthrones do 10" bass drivers and whilst not in the same league of the 15" they will do nice clean bass and will not look to big if designed similar to mine

[IHP]

Lovely looking amp but at 8w pc I'd withdraw my recommendation of the Proacs ! Deffo need something more sensitive as suggested.

[hruyter]

how can you tell it is 8W?

is there some way I can confirm the wattage, measure it or deduce it from the internal components. I have the schematic by the way ...

I will ask the man who built it tomorrow as he has gone to bed already.

what is SET(P)
and what does open baffle mean?
or is that just the term used for the feeling a newbie gets when trying to figure out what speakers he needs :lolsign:

Hill

[John]

Open Baffle Means that the drivers do not fit into a standard box they usually just a piece of wood with holes cut for the drivers (in very simple terms) What this gives you with the right drivers (most drivers will not work this way) is a lack of coloration, a very simple build and great sound per pound. The major issue in the past has been the bass but there are several ways around this
http://theartofsound.net/forum/showthread.php?t=9466
I let someone like Ali Mark or Lurcher to explain SET

[hruyter]

thanks for the link and thanks for the compliments on the amp. I will pass them on

IHP you mentioned tube rolling in your intro post, what does it mean?

anyone close to northwood I could take my amp to to plug it into some different speakers to hear different results?

I reckon I could build a pair of those, I particularly liked the smaller ones.
food for thought

by "going active on bass" does that efectively mean having a sub woofer circuit and driver in the bottom of each unit?

is this necessary?
I assume the active bit means amplification of the low end using transistor based unit?

since i am using my Yamaha AV amp currently as pre-amp I guess I could get the same effect by using the sub out from that and sending the bass only to the sub this would probably mean I cant use the pure direct circuit any more (will have to rtfm)

could I get away with smaller drivers in this case

my current sub is soooooo rubbish so will need replacement though


ohhhh my poor head ... :scratch::doh::scratch::doh::scratch:

Hill

[lurcher]

As from the look of the amp there are only two EL34, and assuming its stereo, then its a single valve per output stage. So it will be single ended. The max rated dissipation of a EL34 is 25W. Assuming the amp stays in class A1 (explain later if needed, but leave that for the moment) then the max power out is 25% of the valve dissipation. 25/ 4 = 6.25. I allowed a bit of clipping, and EL34 can be driven up to 30W on a good day, so finger in the air, I said 8W as the output power.

SET = Single Ended Triode.

The EL34 is not actually a triode, its a pentode. but its possible to use it such that it behaves like a triode. Its also possible to use it as a Single Ended Pentode, hence the SET(P) I used, as without knowing the circuit I can't tell.

[Ali Tait]

Hill, the power output of your amp is set
a) by the output valve that is used (in this case EL34)
b) by the fact it is a Single Ended amplifier.

In this topology of amp, there is a maximium power output that is available from using an EL34, as Nick quite rightly says, around 8w. To get more power, you'd have to use a different valve and redesign the amp to make the most of the new valve you selected. This is how valves work, there is only so much power output available from a given valve. You can get a bit more by driving the valve harder, but this will seriously shorten it's lifespan. It's best to run valves within their specifications to give the longest lifespan and best reliability.

[The Grand Wazoo]

................and tube rolling is trying out different brands and variants of valve type equivalents to try to find the sound that you most favour

[Ali Tait]

I'd suggest something like this would be a good match to your amp, though it wouldn't give huge bass-

http://www.audio-talk.co.uk/phpBB2/viewtopic.php?t=3349

[Ali Tait]

Or check this site out for some very good full range diy designs-

http://www.frugal-horn.com/

[John]

I am pretty close to you Cricklewood. My speakers use 15" drivers so a bit big, but you more than welcome to hear what open baffles do: be prepared to be scared Lol