Any Good (valve amps)

[2zenmonks]

I am thinking of getting a new sound system and came across these -

T-2 Amplifier | neuhaus laboratories (http://www.neuhauslabs.com/amplifiers/)

However, I know absolutely nothing about sound systems. I bought a Sharp Optonica about 30 years ago and it has seen much better days, so any advice about these amps would be much appreciated.

And while I'm at it... I am thinking of building these speakers, how do you think these would go with the amp?

The kit can be seen at ...
MDF Transmission line enclosure kit (pair) (http://www.decibelhifi.com.au/prod146.htm)

It says that these can be made as either vented design or transmission line boxes. What is the difference between a vented design and a transmission line speaker box?

and the drivers at ...
JORDAN JX92 4" metal cone wide range driver (each) (http://www.decibelhifi.com.au/prod145.htm)

I live in a small apartment so I'm not looking for anything with a lot of grunt. Most of the music I listen to is either jazz or classical. I also want to play my flat screen TV audio which has optical audio connections through the system, as well as my iPod.

Thanks for any advice.

David

[HeadScratcher]

Just finished typing up a lengthy post and got a BSOD :(

Ok lets see if I can remeber what I wrote.
Interesting choice you made there.. Valve amps are generally the domain of the horn crowd that like the "warmth" of the valve amp, which is a direct opposite of the metal driver you have chosen. Also horns are generally of a much higher effiecency so they don't need so much grunt from the valve amp.

Also intersting that you are looking at a transmission line cabinet for a 4" driver. It can be made to work but an unusual choice.

As for a 4" driver doing 40Hz - 20kHz it will be a cold day in hell when it gets close to either end of that spectrum. What they don't tell you is at what SPL they reach those figures (SPL is Sound Pressure Level or volume to you and me) by the time it made either of those figure it could drop to as little as 1 dB which you wouldn't hear.

Consider for a moment ambient noise is many many times greater than that. You would be lucky to get to maybe 200Hz. I also notice that you didn't mention a tweeter, so I am guessing that you think you can do it with just one driver?

Again not going to work that 4" is going to run out of puff long before your music does. The decent driver manufactures will provide you with a frequency response chart and a figure that is more like +- 3 dB from the average SPL. +-3dB is sort of an industry standard that is considered a significant enough drop to stop measuring.

Just to give you some kind of comparision to work to, if it produced the 40Hz at 1dB it would be making less sound then someone breathing. http://en.wikipedia.org/wiki/Sound_pressure (http://en.wikipedia.org/wiki/Sound_pressure)

So what would I recommend for someone who likes jazz and classical on a budget?
I would be looking at something like this http://zaphaudio.com/ZRT.html (http://zaphaudio.com/ZRT.html)
The guy is very cluey and has already done all the research of what works for you, you just need to build it.

These guys seem to have a relationship of some kind with ZaphAudio and sell kits based on his designs. http://www.madisoundspeakerstore.com/index.php?p=catalog&mode=search&search_in=name&search_str=ZRT+2-Way (http://www.madisoundspeakerstore.com/index.php?p=catalog&mode=search&search_in=name&search_str=ZRT+2-Way)

I can personally vouch for the ScanSpeak Revelator 18W/8531G as my current speakers use two of them per speaker in a modified configuration. They are well respected by some big names in the speaker business.

So if you still want to do the cabinets yourself the kit caters to that and you can save a few dollars in the process.

[2zenmonks]

Thanks very much Headsratcher.

Like I said in my first post, I know absolutely nothing about HiFi equipment. Your suggestions were spot on for what I am looking for, although expensive for me (pensioner) I will just have to save up to get what you recommend but I think it will be well worth it in the end.

I did not understand some of what you said (bit of a learning curve there) but it seems that you really know your stuff so I will go by what you have said.

Now I have something (else) to look forward to.

Thanks again.

David

[damian]

I'm going to try some uncharacteristic diplomacy here.

I don't know you so I don't know whether your building this to save money, because you think it'll do something magical for you, or because you WANT to build. If the latter ignore what I'm about to say.

I've been building valve amps for 20 years. Mostly for guitars. I'm not an audiophile. I had a quad system for a while, KT66 based. I've fiddled about with some of this supposedly high end stuff.

Pretty much valves have lousy frequency response, so they sound a bit compressed, hence the "warm" sound. They also tend to have more odd order harmonic distortion. The modern ones are incredibly expensive and most of the modern components aren't that great, not juts valves but output transformers capacitors etc. The trannies can be a bit sterile, chasing efficiency.

Anyway for what it's worth I went back to good old transistors years ago for the record player. Cheap, nil maintenance, crystal clear.

Have you looked at electrostatic speakers for a bit of fun ?

I still make valve guitar amps, but that's a whole nother crock of fish.

Anyway whatever you do remember to have fun :)

[HeadScratcher]

Hi David, if there is anything you don't understand just ask...
Comparing apples with apples they are similar in price. AU$209 vs US$237 + frieght / gst.
Ok its dearer but well worth. As for the other bits in the kit, no 4" driver is ever going to deliver a decent end to end experience worth listening to. So really to get half decent sound you are going to need the tweeters and the crossovers anyway.
Bit like buying a hand saw to do the job of a circular saw, sure it will sort of do the job but it will be full of compromises.
I would be seriously amazed if you didn't like the sound of that kit. (note they will need a decent break in period).
Hasaudio always seem reasoanbly cheap to buy from. Haven't purchased anything from them yet...
http://www.hasaudio.co.nz/scanspeak-revelator-speakers-c-33_227_298_299.html (http://www.hasaudio.co.nz/scanspeak-revelator-speakers-c-33_227_298_299.html)
http://www.hasaudio.co.nz/revelator-midwoofers-c-33_227_298_299_302.html (http://www.hasaudio.co.nz/revelator-midwoofers-c-33_227_298_299_302.html)
but they have the ScanSpeak Revelator 18W/8531G for AU$185.79
The postage from NZ is also likely to be cheaper than the US and provided your goods and freight are under AU$1000 you don't have to pay Greedy Sales Tax.
the 3004/660000 are going for AU$183.37
http://www.hasaudio.co.nz/tweeters-c-33_227_298_304_305.html (http://www.hasaudio.co.nz/tweeters-c-33_227_298_304_305.html)
2 x $185.79 = $371.58
2 x $183.37 = $366.74
= AU$738.32 + postage
If you could then get the Zaph crossovers from Madisound you could be better off then buying all the kit off them.
The trick is to make sure that you factor in all your freight and other charges before you start purchasing.
I just purchased a digital crossover from Denmark, the bank slugged me nearly $100 converting the money and sending it, then the govt hit me up for over $300 in GST then another $55 for some other tax and another $16.50 for some other freight associated cost.
It all adds up so factor it in...

[Zaphod]

I am thinking of getting a new sound system and came across these -

T-2 Amplifier | neuhaus laboratories (http://www.neuhauslabs.com/amplifiers/)


NEVER assume:

Valves = good.
Transistors = bad.

There are good examples of both types of technology. At the price quoted, the amplifier is likely to be of Chinese origin. Not this is not necessarily a bad thing, but the Chinese have a tendency to build for cosmetic appeal first and sound quality last. The most important thing (by a very considerable margin) with any valve amp, is the output transformer. Quality output transformers are VERY time-consuming to build, using top quality materials and are, consequently, expensive. A good quality output transformer for a 20 Watt amp would typically run to a couple of hundred Dollars. Or more. AND, you need two of them. AND, you need power transfomer, valves, caps, chassis and all the other stuff. Make of that what you will. My experience is that Chinese manufacturers don't care about output transformer quality. With price concious products, something has to give. Usually, the manufacturer cuts corners on the stuff you CAN'T see, or don't understand. Few buyers understand how to spot a decent output transformer (you need to strip it apart - which takes almost as long to do as it does to build it), so that is where corners get cut. Every time.

For 800 Bucks, you can buy a pretty decent transistor amp (new) or a very good transistor amp (used). 800 bucks is likely to get you a mediocre valve amp.



However, I know absolutely nothing about sound systems. I bought a Sharp Optonica about 30 years ago and it has seen much better days, so any advice about these amps would be much appreciated.

And while I'm at it... I am thinking of building these speakers, how do you think these would go with the amp?

The kit can be seen at ...
MDF Transmission line enclosure kit (pair) (http://www.decibelhifi.com.au/prod146.htm)


I'm a big T-line fan. However, time has moved on and I reckon you can probably do better with a regular vented enclosure, using more than a single driver.



It says that these can be made as either vented design or transmission line boxes. What is the difference between a vented design and a transmission line speaker box?


T-lines are generally larger. Without going into technical detail, a T-line is, essentially, a long tube. You could, for instance, build the thing from a length of 100mm sewer pipe. With the same line length as the folded one in the wooden box, the results would be very similar. A vented enclosure utilises the resonance of the driver and the resonance of the box to provide an extended bass response.

Both systems have their positive and negative aspects, but, IMO, a well designed vented enclosure, using a bass driver and tweeter will provide a more balanced response, in a compact enclosure, with somewhat higher efficiency.




and the drivers at ...
JORDAN JX92 4" metal cone wide range driver (each) (http://www.decibelhifi.com.au/prod145.htm)



I am familiar with the old, metal cone Jordan drivers. They were delightful, if not a little fragile and inefficient. The new ones appear to be more efficient and more or less conventional in design. I suggest you widen your scope to include other drivers from companies like: Seas, Scan Speak (expensive, but very good), Vifa, Peerless, et al. Again, my suggestion would be to look at a bass driver of around 5.25", combined with a suitable tweeter, in a vented (bass reflex) enclosure. It should be more compact, more versatile and capable of better performance.




I live in a small apartment so I'm not looking for anything with a lot of grunt. Most of the music I listen to is either jazz or classical. I also want to play my flat screen TV audio which has optical audio connections through the system, as well as my iPod.

Thanks for any advice.

David

Fundamentally, the best way to choose any hi fi component, is NOT by looking at a web page. It is by listening for yourself.

[HeadScratcher]

Valves = good.
Transistors = bad.


Spoken like a true tube fan :) Can't we compromise a little ;O) old conrad-johnson news (http://www.conradjohnson.com/It_just_sounds_right/news4.html)

2zenmonks to put some balance to this part of the question, no amplifier is without compromise. We all have our own music preference, and there is good and bad in each design, it ultimately comes down to what you prefer, or in most cases what your budget will allow.

I like the extreme opposite of Zaphod, I quite like the Class D (digital) amps, but they have their own set of problems just like tube amps have theirs.

Bang for buck and really that is where any budget aware builder needs to start, you are much more likely to get better sound out of a cheap anlogue or digital amp for the money you want to spend then you are a cheap tube amp.

There are some very nice tube amps out there but they dont come cheap (the one in the link goes for around $7.5k rrp, I was looking at them myself)

While I disagree with Zaphod on Transmission Line being past its used by date, I do agree with his suggestion of use a bass relex or commonly known as "ported" enclosure like the one in the kit I suggested.

I think the TL has its place but for what you are doing a ported or sealed cabinet is going to be more sound sensible. Probably not as challenging to build but sound results will be more predictable.

What is your ultimate end goal from the project, to build a technically difficult box to test your wood working skills, or the sound of the speaker produces?

If it is to test yourself a square box isn't likely to provide much of a challenge... Not to say you couldn't make it non square and keep the same volume :)

[Zaphod]

Spoken like a true tube fan :) Can't we compromise a little ;O) old conrad-johnson news (http://www.conradjohnson.com/It_just_sounds_right/news4.html)


Dunno if you deliberately mis-quoted me or not. I'll expand on my comments:

NEVER ASSUME the following to be fact:

Valves = good.
Transistors = bad.
Valves = bad.
Transistors = good.
Class A = good.
Class D = bad.

There are good and bad examples in all the above. Is that a little clearer?



2zenmonks to put some balance to this part of the question, no amplifier is without compromise. We all have our own music preference, and there is good and bad in each design, it ultimately comes down to what you prefer, or in most cases what your budget will allow.


Which is pretty much what I stated, with the proviso that valves, at the price point mentioned, are not a smart choice. Far too many compromises will have been made in such a cheap valve amp.



I like the extreme opposite of Zaphod, I quite like the Class D (digital) amps, but they have their own set of problems just like tube amps have theirs.


Nothing wrong with Class D amps. They are entirely appropriate for mid-fi and subwoofer applications. High end they're not. At the price point specified, Class D might make a reasonable choice. Or not.



Bang for buck and really that is where any budget aware builder needs to start, you are much more likely to get better sound out of a cheap anlogue or digital amp for the money you want to spend then you are a cheap tube amp.


On that we agree. Valve amps don't start getting particularly interesting at much under $2k. For the $800.00 price point, there are some quite decent transistor amps available and some outstanding second hand bargains around.



There are some very nice tube amps out there but they dont come cheap (the one in the link goes for around $7.5k rrp, I was looking at them myself)

While I disagree with Zaphod on Transmission Line being past its used by date, I do agree with his suggestion of use a bass relex or commonly known as "ported" enclosure like the one in the kit I suggested.


Not so much past it's use-by date, it's just that modern, well thought out reflex enclosures can provide a great deal of benefit, with almost no downsides. If the OP wants to play with a T-line, then sewer pipe works a treat, costs very little and looks cool (or appalling, depending on your POV). And yes, I've built a few sewer pipe T-lines. And a few timber ones as well. The biggest stood 2.1 Metres X 600mm X 500mm. Bass AND mids were T-line loaded. Bastard was too damned heavy though.



I think the TL has its place but for what you are doing a ported or sealed cabinet is going to be more sound sensible. Probably not as challenging to build but sound results will be more predictable.


Yep.



What is your ultimate end goal from the project, to build a technically difficult box to test your wood working skills, or the sound of the speaker produces?

If it is to test yourself a square box isn't likely to provide much of a challenge... Not to say you couldn't make it non square and keep the same volume :)

Got a mate who used to build his boxes from lumps of hollowed out tree. Sounded like crap, but looked very cool.

[HeadScratcher]

Sorry Zaphod I missed the line above which reversed the statement, making my post fairly redundant.

Sometimes wearing glasses for reading now I am starting to miss things, part of the joy of getting older.

probably off topic since we both agree for the budget specified we both wouldn't go valve but just out of curiosity what would you buy if you had a couple of thousand to spend on a valve amp for top end drivers.

the reason I ask is I have just bought some Raal 140-15D AM tweeters and considering valve to power them.

[Zaphod]

Sorry Zaphod I missed the line above which reversed the statement, making my post fairly redundant.


No problemo. I've been guilty of exactly the same thing many times.




Sometimes wearing glasses for reading now I am starting to miss things, part of the joy of getting older.

probably off topic since we both agree for the budget specified we both wouldn't go valve but just out of curiosity what would you buy if you had a couple of thousand to spend on a valve amp for top end drivers.

the reason I ask is I have just bought some Raal 140-15D AM tweeters and considering valve to power them.

As always, I'd suggest that you locate an ME power amp, as they provide the best performance attributes of solid state amps, combined with the best attributes normally associated with valves (no messy output transformers to needlessly elevate the price and reduce performance). Best of all, they're Aussie made and supported. I just serviced a 30 year old model and the guy who owns it reckons it beats the pants off anything below $10 - 12k. He paid a grand for it and spent another $500.00 to bring it back to new spec.

If you MUST have a valve amp, then this guy winds his own output transformers to astonishingly high standards:

sb343971 - Home (http://www.westonacoustics.com/)

Workmanship is first rate, he is a real decent guy who is dedicated to the best. Like all good manufacturers, he will not compromise (like ME Sound).

[HeadScratcher]

Thanks Zaphod. Don't really want valve but I want my tweeters to sound musical without colouring the sound too badly.

if I could achieve that without valves all the better. Will keep an eye out for a second hand ME850, looks like a very nice amp.

[Zaphod]

Thanks Zaphod. Don't really want valve but I want my tweeters to sound musical without colouring the sound too badly.

if I could achieve that without valves all the better. Will keep an eye out for a second hand ME850, looks like a very nice amp.

Oh yeah. Very nice. I note that you are in Sydney. I have plenty of amps (including an ME850) available. You're welcome to borrow one for a week or so to see if it is right for you. If not, then return it. Easy peasy.

[HeadScratcher]

Thanks Zaphod, once I get things to a steady state I would be keen to give it a listen. I am thinking of making a trip to QLD to pick up some bits and pieces of stereo gear including an analogue amp I already have in storage. so it would be nice to compare different types of amps on the tweeters to see what does and doesn't work.

We better stop hogging the thread, but your welcome to post comments in my build thread...