h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

first off,thank you spiny for founding the hifi club and including my eclectic (some may consider strange)collection of components.the oki is a model 555,the turntables 212 electronic,the SAE preamp a mark nine.i use monster cable interconnects where i can.planning on removeing technics dubbing deck,so i can use shortest possible interconnects on the onkyo.i call the four 12s fullrange because they use no crossovers midrange or tweets and get the full signal. what i consider a full size cabinet would be one that could house two 12inch speakers in a front faceing baffle.

Hi james, glad to welcome you on board. Feel free to start any discussions on any subject - that's what I want the club to be about.

Interested in what you say about full range 12-in speakers. Of course, feeding them a full range signal won't turn them into full range speakers unless they're specifically designed as such. Most 12-inchers struggle to produce anything above 8kHz unless they're fitted with a second smaller cone sometimes known as a parasitic tweeter, and even then they'll probably only reach 12kHz or so. But maybe you have a model I've not heard of in your boxes?

The big advantage of having a single driver to cover everything is that the phase coherence is vastly improved by not having any crossovers or other voice coils in the signal path. The result is far better imaging and perception of stereo spread. That's usually why the stereo effect sounds amazing in your car or from your computer speakers. Sounds like you're on to something there.

your right the 12s dont do much at the top end,im not asking them to do much in the bass range either.i like the presence they give me in the midrange.once thought i needed at least a 12 inch speaker simplely because thats what was originaly(most likely) being useed to moniter the master recording.have since accepted that a 10 can sound as good,(the infinitys opened my ears to this)sometimes maybe even two 8s. have a freind who must have 15s because he thinks they do best on piano parts.dont like the sound of the parasidic type tweet or whizzer cone,dont like band pass type sub woofers.dont like horn tweeters,but i have a pair im going to experiment with.they dont have voice coils,they have a stlylus attached to the center of a dome,

further clarification, or confusion perhaps.mine i consider a bi amped system.the mains take care of everything, as flat or uncolored as possible,while the second amp is reinforcement(the four 12s)giveing me better control of the midrange,ive got a ear that cant tolerate harsh mids.

Hello, I'm new to the guide and am seriously interested in music and how to reproduce it. Most of you seem to have reasonably powerful transistor amps ( I may be wrong... ) but have you ever tried building any of your own stuff ? I've made a few amps and disk stages and regularly rebuild the ( incredibly poor )output stages of many CD players for friends. Recently I've really got into single-ended amps, both valve and transistor. Ever heard any ? The ones I've heard are just so special and knock spots off my ( heavily reworked ) Sugden A48.

Hi Warlie - glad you found your way here and welcome aboard!

Also glad to hear the noble art of home-brewing (as we used to call it) is alive and well. I have done a bit of work with a soldering iron myself, but usually to tweak rather than to build. I had some fun a few years ago with a Quad 405 which I brought up to a more modern spec (gold-plated phono inputs, heavy duty speaker binding posts, decent internal wiring, new PSU capacitors, etc). It ran my main system for a while until the B+W monoblocs came along at an irresistible price. Now I'm a firm believer in keeping speaker cables as short as possible, so the Quad's awaiting a new role in my other system as soon as I get my Hi-Fi World kit speakers built (sometime this year...).

I haven't heard any single-ended amps since the days of my youth when I used to muck about with an old Ferguson reel to reel tape recorder. An EL84 used to put out about 3 watts mono through a miniscule transformer, and since my dad used to run a Rogers Cadet which could manage 8 watts per channel, the tape recorder got scant attention. I believe some of the Pass labs amps I've read about are SE transistor, but waay out of my league. And the Quad's current-dumping technique uses a single ended stage which the bipolar output stage current-mirrors - it sounds pretty good, but it's not the same, I know.

Anyway, let us know what you've been up with that Sugden, and any other DIY thoughts you want to share. I would be interested in any disc pre-amps you've tried that sound good. And why not write up your current system so that I can give you your own room?

BTW Pheroneous, I should really update your room as you're now using those MF A3s, aren't you?

Hi Spiny, glad to be here.

My SE mosfet is actually a copy of a Pass Labs design, it has only 1 gain stage and produces 10 W of extraordinary music.
The disc stage is a tweaked version of a Hi-Fi world design using Analog Devices electronics, 0.1% resistors and a whopping power supply - it is excellent, makes CDs sound anaemic.
The system is like this -

Thorens TD150 MKII with RB300 and ATF5 m/c cartridge. External class-a power supply for 33/45. Silver cable to passive pre - home design, Alps blue velvet pot and high quality switch.
Leak Troughline valve tuner
Sony TCK611S dolby S tape deck
Philips CD303 16 bit 4X o/sampling cd player with reworked analogue output stage. Silver-plated interconnect to pre-amp.
Sugden A48 - pre is bypassed, bias current increased, whole amp has been rebuilt with high quality components - sounds very good.
TDL RTL3 floorstanders (reworked crossovers) connected to Sugden via triple and earth household single core wiring cable - really excellent.

The whole system runs off a 625 VA isolating transformer from the mains.

Most important of all are the 800-900 lps that lurk in my listening room, covering nearly all types of music.

Also hiding in the room is an SE valve amp that uses 2 EL34s a channel to give 8-10 W of almost identical sound to the Pass labs copy. In fact, the circuit diagrams for each design are almost identical.
( I also have lots of kit in the garage - Leak Sandwich speakers, B&Os, more amps, a Garrard T/Table with the world's most extraordinary arm etc. )
In an ideal world, I'd love a Townshend Rock Reference for my LPs, but it's a bit dear, perhaps one day.
Well, I've gone on a bit, hope you've stayed with me.

Hi Warlie, your "room" has now been built. Good to have you here.

Just to take your points in order - I suspect you're right to mention the large power supply for your disc stage. In fact, I wonder whether most preamps aren't under-supplied. I have an ex-BBC control box with a toroid in it as big as some power amps, and it sounds great, but it does not pass the domestic acceptability test...

Erm - how do you power a TD150 from a class A amp without needing a water jacket?

Interesting approach running everything off an isolating transformer. What benefits does that bring?

More questions later - gotta run just now.

Hi, thanks for the room, it's so roomy.
The Thorens' motor only uses about 8-10W, so a class-A supply only runs at double that power - not a lot.
An isolation transformer always appealed to me because I noticed the sound of my system improving greatly at night. I considered that this might be due to a cleaner supply, fewer other users on and therefore the voltage was actually higher and more stable. I measured the mains and found most of this is true.
The toroid I use is a 625VA one, effectively it acts as a regulator, since the whole system only draws 100VA maximum.
The second effect is that of a very severe low-pass filter, 'cos it's like a big inductor - cuts out spikes etc.

Ah. I thought the Thorens used a synchronous mains motor - I must be thinking of an older one.

Interesting about the mains isolation. So is that something you've made up - an f. big toroid from Maplin in a box-type-thing, or is it a commercially available isolation transformer you use? And what sort of cost are we talking about?

The Thorens does use a synchronous ac motor - but only about 60 V ac is required. The p/supply just oscillates at 50 Hz for 33 1/3 and 67.5 Hx for 45.
The toroidal is a 625 VA from RS, I think. It's all home-brew, steel box, lots of VDRs on input and output and a 15A fuse and switch ( the lights dim and 13A fuses fracture on turn-on due to the massive inrush current ). Total cost about £40. Worth it.

First time I've been back since Rupert. So, you can change me if you want to, Spiny. I've had the A3 system installed for some weeks now, and am gradually working my way through all my CD's. Faultless, impeccable, spot on, but...(and here I know you will all sympathise)...there's something missing! (Isn't there always???) I remember when I first switched on the typhoons, and went Wow!!! It doesn't happen with this new stuff, but I can't pin it down. The detail is there, the soundstage is there (well, better than before), perhaps lacking slightly in the bass. FM radio is much better. I think its what the magazines call 'presence'. Cables. Thats it, I shall buy some speaker cables! Great big fat ones perhaps...or some nice Van den Hul....any ideas???

This may sound stupid, but just try triple and earth house wiring cables ( particularly if you bi-wire ). You can get them from almost any electrical outlet. They are single core copper, cost about 30p or less per metre, and you may just find them to be the most balanced sounding connection, as I do. They have 4 strands, each about 1.5mm diameter, and you just arrange them into 2 pairs and terminate them how you like. Since they are so cheap, you have very little to lose.

I'm missing something here. I thought the point of this game was to spend vast amounts of money that you don't have on 'improving' your setup, and then, a few short weeks later, deciding its not quite right. I didn't know you were allowed to do it cheaply!

Cheap tweaks! We love em! We justify them by telling ourselves we have to spend so much money elsewhere in our system in order for it to be revealing enough for us to tell that the cheap tweak was a great way to save money.

Pheroneus - you've still got the Typhoons, what about bi-amping? One box to do the treble, the other the bass, and see which way round puts the excitement back...

got a room that sucks out all the bass?install your speakers so their woofers are at ear level.may be trying 15's in place of 12's picked up a pair to macth the pair i had,enclosures are the concideration,what i have in the rear are large enough,so its just a matter of duplicateing them,and then move the chimmney in the house 4inches to the left to get the right one in.at this presise moment i,m listening to coocoocacooo it came on,must have pushed shuffle...

just thinking got a hi-fi setting in,in the hall that has a 15,a 12,and two or more tweets,a hiker from the late forty's,it does quite well with piano parts....the entire orch. really,also has slight hum,maybe four of these,thinking of useing pioneer qx 949,now in kicthen for reinforcment channels.it's got a amuseing round vu display,and lots of places to plug things in.

just thinking got a hi-fi setting in,in the hall that has a 15,a 12,and two or more tweets,a hiker from the late forty's,it does quite well with piano parts....the entire orch. really,also has slight hum,maybe four of these,thinking of useing pioneer qx 949,now in kicthen for reinforcment channels.it's got a amuseing round vu display,and lots of places to plug things in.

I'd be interested to see if you're right about putting the woofers at ear height, james, but the Tannoys are floor-standers and dual-concentric as well, which means 1. the woofer already is at ear-height 2. they're already too tall for me to put anything under without causing a domestic riot.

Your speakers in the hall sound more like PA than hi-fi, but if they sound good, that's reason enough to use 'em. A 15 and a 12 together should certainly make a good job of reproducing piano. There's a lot more bass energy in a Steinway than most systems can punt out. My Tannoys won't do it either

Going back a bit, Spiny, to your reference to the Typhoons, which you rightly surmise that I still have. I did have them bi-wired (One L, the other R) but couldn't go for a true bi-amp because the speakers are concentric and thus the tweeter was not accessible separately, at least not to my limited expertise. There is a separate bass speaker, and I might add weight to that by bi-amping, but feel I would lose the more important mid-range. I think life would be far too complicated to bring them back into the system now. The A3 is pretty good now its settled down, especially on those odd occasions when I can get the volume up a little.