Wm goes Thermionic

very good point. instantaneous output is probably much higher than the 8 watts reported. i'm sure that a good stiff power supply is more important than continuous output.

 

Hi,

The problem is that there is no realistic measure for SPL. So within reason every manufacturer makes up their own measurements. Now a 3db difference in cclaimed SPL is halve/double power, not exactly small fry. Also, by studiously omitting to account for thermal compression and listing max SPL as RMS Powerhandling in db on top of nominal SPL/1W they make up a another 4-6db.

The claimed MAX SPL for unclipped programme (well approximated by pink noise) may actually be as much as 10db below makers spec when measured using my pink noise slow average methode.

Yes, modern London strikes me as having more than a touch of the "Dark Empire's Capital".... Then again, maybe I'm just on a different plane of the multiverse....

Ciao T

 

blake - almost certainly 6 db higher I would bet. The ability to deleiver high peak to continuous ratio is probably more important than outright power.

3d - unfortunately yes. and the spec sheet supplied with my speakers (and almost any other speaker) doesnt specifiy the conditions. What I will say is the volt radial bass driver in my speaker is inherently more linear than is the norm and suffers much less from thermal compression. I beleive the effects are also counted in. As you say it depends on the window of measurement and many other factors. They go extremely loud without audible compression or strain and they do so cleanly with very little distortion - which makes listening at higher volume more palatable. That second trilogy was some far out stuff.

 

WM, yes, I went with the power amp as well.

Potted history:
Last year, I downgraded from a top of line olive Naim system to a chrome bumper Nait 2, liberating around five grand of cash in the process. I'd come to the conclusion that the benefits that the bigger system gave were not really significant, whilst the cash was As a consequence, the cash sat around and I was quite happy with the Nait. However, when I was changing the LP12/Aro/Geddon for a Spacedeck, I heard the MiniMax pre-power and it really offered a sound that I didn't think was possible for the money.

Sure, it doesn't kick out huge swathes of power, but in my modest room (18'x16' with a 10/11' ceiling) and modest (cheap) Royds, I get all the volume I need and/or want, and it's far more controlled than with the Nait. Bass goes quite a bit deeper and the treble goes far higher than with any Naim I've heard. What you lose over the Naim kit is that extreme leading edge emphasis, which I liked, but now realise to be a colouration which I can live without. The MiniMax pre-power is very fast, but what's neat about it is the ability to 'tune' the sound by swapping tubes. Changing the first tube on the pre for a NOS Radiotechnique 6X3 from the early sixties made the sound a tad more 'electrostatic' - if you know what I mean - at the expense of a slight lift in the treble. I'm going to replace the middle tube with either a NOS Mullard ECC82 or NOS Philips E80CC gold-pin, and the final tube with a NOS Mullard ECC82 (both Mullards won on EBay).

I could waffle all morning about the MiniMax amps, such is my positive impression of what the designers have achieved at frankly giveaway prices. The fact they sound far better than my memory of my 52/SC/250 (direct comparison not possible as it was sold) makes me realise how much of a bargain they are, and they sound to my ears even better than any of the 552/500 systems I've heard. Obviously they don't go as loud, or probably as deep, but they do the important bit better, IMHO.

John

 

fascinating discussion.

I have just gotten a basie from hongkers and am going to experiment with some easy to build pre circuits and phono stages, I even tried 3 passives with some good pots I had around which were all totally different, i liked them all, I had noble, pec, and vishay stepper, they were all totally different, and I was really sceptical, I thought a vol control was a vol control....

be interested to know the minimax circuit, probably volt gain and cathode follower, or srpp, something very basic.

maybe I will get onto a euridice...in time...but lots of fun to be had, I am doing a pro build this time after learning how to contstruct to a pro std.

tag strips and all that, no messy valve wiring a la meixing, tho they do that very well, can get a bit fiddly tho'.

boards and strips are more accessible for tweaking. that and turrets are for final builds.

 

John,

Have 2 cryo'd Mullard 4004's coming and I've managed to find a couple of diamond bottom Telefunkens, though they wern't cheap. as for the Rectifier tube, I'm waiting for answer back on a Genelex Golden Lion. (these are a difficult find, so I@m keeping my fingers crossed)
I'm pleased with the MM, for the cash its a steal & a £100 worth of mods really do take it to the next level.
Congrats on finding your musical nirvina. Wm

 

welcome to the club

It is very small and distinctive club, now with 2 Zerogain members!

I think you will be delighted with it when you finally get it built. There really are a thousand build options, and so many mod alternatives it can make your head spin.

Which kit components did you go for?

 

tony for your sake i hope you mean cv4003 as that's the correct UK military code for the 12au7... if you happen across more than 1 of the genelex 6x4s, i might be interested in one!


also i have heard it said.... (in hushed whispers....) that the telefunkens are great but not really worth the asking price. there are some other tubes that can equal / better it for less. (now who does that sound like??? )

 

WM, let me know if you end up with spares of any decent valves - I have a spare 6x4 as described above, and may end up with a spare E80CC gold-pin. Given that NOS valves can last for 5000-10,000 hours of use, and given I only turn the kit on when I want to listen, I reckon I'm good for the next 5 to 10 years based on current listening habits! Send me an email and we can talk more about valve choice (this goes for you, too, bottleneck & blakeaudio): jtcedinburgh is the email address at gmail dot com.

Now, if only I could guarantee to get 5000 hours out of my Helikon MC (I'll be happy with 1500, which is still a LOOOOONG way off... )

John

 

Blake,
4004 is the correct number for a Mil spec box plate unit New

 

Tone
Mine are box plate, CV4003 which is 12AU7 (ECC82)
CV4004 is 12AX7 (ECC83)

 

the only other tube you can use in the minimax is the ECC80 / E80CC (special quality) i can't remember what the corresponding code is for that one, but the cv4004 is definitely the mil code for the 12ax7, which can't be used.

the ecc80 has a higher voltage rating than the ecc82 /12au7, and it is recommended that this is used in the buffer stage as it can sound a bit harsh in the amplifier section...

 

Hi Tone,

Blakeaudio and Andy are correct. The English military spec for an ECC82/12AU7 is CV4003. This valves has a lower amplifing factor than the Ecc83/Cv4004 but the pin layout is the same.

There are many different Ecc82/Cv4003/12AU7 valves out there at many different prices. Some were built for various usages such as computer and miltary. The sites below give a run down on the many types.

http://www.r-type.org/exhib/aai0265.htm

http://www.machmat.com/sales/ecc82.htm#e82cc

http://www.audiotubes.com/12au7.htm


SCIDB

 

check out a review here...

http://216.239.59.104/search?q=cach..._e.html+eastern+audio+minimax+schematic&hl=en

 

12BH7's are also worth thinking about in place of 12au7. Again draw more current.

Hope you didn't get the wrong valves Tony

 

Seems Wm is havng sight problems this morning LOL!!!, you 4003's they are sir quite correct

 

Ian

Brian Cherry of diyhifisupply.com who manufactures the Basie pre amp is a very nice Canadian gentleman who lives in Hong Kong with his Chinese wife. Brian was a teacher before he started his diy audio business. He has a passion of valve amps, turntable and high efficiency speakers. I have met him twice and he is always very pleasant to talk to. He really rates the Loth single driver speakers highly.

He runs the company with the help of one young chap. He gets his irons and chassis from China and he told me that the quality is quite good nowadays.

Regards
Hon

 

I bought a few nic - naks last year from Mr Cherry just to test the water so to speak,everything was fine until Benny filled in the HK customs export form and accidently added a couple of 100 extra US dollars.

Did I get charged VAT on the crossed out part - Yes
Did I try to claim the VAT back from HM Customs - Yes
Did I get the overpayment back - No
Does Benny care - I don't think so
Have I bought anything since - no

 

I've tried various ECC82's in my Kit88 and the Mullard 4003 was my favourite, orange globe Amperex was not bad either
I didn't care for the Telefunkens but see how you go

 

An inside shot of the MM with the suppiled mods




I've started to do a few bits and bobs to her............