Audio Project Amplifier Speaker Loudspeaker Kit
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A late arrival... - Click HERE for Original Thread
acoustixman
Greetings, all! I hope this finds you well.

I don't know what took me so long to "assimilate" as I am a very DIY-hard individual in all areas, especially audio (probably a cheapskate in the minds of some)!! It's good to be here at last! I will admit to collecting a few advisory notes in this forum prior to my joining!! Thanks all!

I've been a D-I-my loudspeaker builder for about a decade; strictly 2-channel music goals... second order all-around; Linkwitz-Riley on the wires, Bessel~Butterworth on the box (control the room: BANG - not BOOM!!)... low fc's and close physical driver placement... ptp wiring; non coupled coils... oblique boxes... VIFA drivers!

Recently, I finally took the plunge and built my first power-amp (in stereo of course); my design has been a bit influenced by W.M.Leach in the front end and G.R.Slone out the back...Full symmetry, 4x-cascode front-end, resistive sources and tails, more diff-gm than low TIM amp, high-beta VA under cascodes, class-A EF buffer, parallelled LMOSFET SF pairs (on 2.73 sq-ft 441K heatsink) in ~class-B... +/-70V rails, 750W / 360Joule supply. The transient response is astonishing ( :smash: ), and that's of course what I live for in the musical world! I don't mean to seem too proud, but unfortunately none of you can hear it for yourselves at the moment, that is unless you live within about 10 houses of mine :devilr: . I intend to give it the full battery (FT/distortion spectra, transient & bandwidth analysis, and whatnot) but I currently lack the means - Tek scope and BKPrecision FG combo proved incapable of resolving any distortion at 1kHz or 10kHz. I'll probably build another or two at 1/2 the power and go with an active crossover.

Vendor Testimonials:
Wakefield Thermal Solutions (TO-3 heatsinks) in NH: excellent, helpful people.
Lansing Instrument Corp (graybox enclosures) in NY: extremely high quality product, helpful advice.
Exicon/Profusion PLC (Lateral MOSFETS) in England: superb product, quick delivery, helpful folks.
ExpressPCB on Internet (ships to me from Oregon): high-quality freeware design package, quick PCB turnaround.
Plitron in Canada: wide variety, custom made at good prices, plan ahead and get order in early, nice folks.
Digi-Key, Allied, Mouser, Newark, McMaster-Carr, Parts Express; always there when you need'em!
Madisound in WI: helpful folks, wide variety, good stock.

Now my question:
I'm seeking a worthy pre-amp design, since my multi-source auditioning system now longs for espousal to my new box. Remote control for source selection and unified volume control are desirable (for improving S.A.F.), not much need for built-in tone controls. I'm thinking about giving it a digital nervous system... Any advice? I might go commercial on a high recommendation... (NAD, etc.?)

b-t-w; how do some users get the graphic ID/handle to the left side of posts?
SY
Welcome to the forum!

To get the cool little avatar, size the picture you want, go to the "user cp" button, choose "options," and at the bottom of the control panel, you'll see the button for uploading the pic.
Jonathan Bright
Greetings from Australia. BTW waht time is it over there? Your system sounds v.good. You'll enjoy your stay.
acoustixman
Jonathan: We're at GMT less 8:00. (Pacific TZ)
Cal Weldon
Hi Acoustixman and welcome to the forums. I see you like home brewing. What type of brewing are you doing?
acoustixman
Cal: I haven't brewed in a shameful little bit of time. By and large, I'm questing for the perfect IPA recipe. Lots of malt body, flavor & conversion (toast a portion in oven before starting) and heavy on the hops (Fuggles to start / Hallertau to finish). I've always wanted to try a lager version (India Pale Lager?!), but I'm sadly without a spare fridge or consistent cold pantry at this time. I'm pretty seat-of-the-pants in the kitchen and probably won't be able to make the right stuff a second time once I discover it anyway. I think brewing provides the ideal mutual complement for the audio practice (i.e. listen to tunes on good kit while brewing, drink brew while designing, crafting and auditioning the next kit)...
ashok
quote:
.....drink brew while designing, crafting ...........

No..No... ... Not if you are into tubes ...:hot:

You could end up in a box .:dead:

Be very careful if you handle high voltages....... have no hooch around.

Welcome to the forum !
acoustixman
ashok: Agreed and thanks for the *sound* advice!! I haven't exceeded +-70V rails, and while that's no tube-caliber, I do treat volts (and coulombs) with respect and resistance. I don't think my wife would be too happy otherwise no matter how great my life insurance is... I do tend to imbibe a little more freely when listening and conceiving [in the circuitry sense] than when soldering and testing. :hot:

Personal note on the tubes; I highly revere them (they are a beautiful and magical component of audio electronics), but I think their best place is in creating sound (guitar and bass amps), not reproducing it. Let's see what arguments that instigates... :cool:

Happy listening and thanks for the welcome!
Bobken
Hi JW,

Welcome from me too.

I once accidentally grabbed +/- 75v rails (i.e. total 150v DC) and I don't recommend it!

Take care!
acoustixman
Thanks Bobken;

I've touched 140VDC with dry hands and it worked out OK...my calluses must be highly ohmic... I couldn't give the same testimony when I accidentally touched a rail-bound resistor lead and GND with one voltmeter probe... Bright flash in my face (always wearing eye protection at the test bench!!), loud bang, and one vaporized resistor. I'm not sure where all the metal went, but I move more slowly at any rate...

I think a part of my joy in audio is the thrill of [coming close to] being in command [at times] of these large quantities of electrical energy. :crazy:
Cal Weldon
Yes, there is something to be said about having a diy while listening to a diy isn't there?

I brewed for years but I now get the U-brew place to do it for me. I simply pick 'er up and pop it in the fridge. (Picture below) Pop it in the fridge? Ya right, the keg weighs over a hundred lbs., so it's a little slower than that.
jleaman
quote:
Originally posted by Cal Weldon
Yes, there is something to be said about having a diy while listening to a diy isn't there?

I brewed for years but I now get the U-brew place to do it for me. I simply pick 'er up and pop it in the fridge. (Picture below) Pop it in the fridge? Ya right, the keg weighs over a hundred lbs., so it's a little slower than that.




CAL you copied Briangt :)
Cal Weldon
J,

He made a kegerator, I converted a fridge

Well two of them actually :D
jleaman
quote:
Originally posted by Cal Weldon
J,

He made a kegerator, I converted a fridge

Well two of them actually :D


one problem His is always full and your's is always empty..:bigeyes:
Cal Weldon
Jason,

Do the math, with two I can't run out, only he can. Also we're straying a long ways from saying hello to our new member.
acoustixman
Cal:

Nice setup! So do you give them the recipe and buy the ingredients and they just follow your instructions?

I wouldn't mind discovering how to keg my own stuff up. The biggest brewing prohibitor for me has been bottling. Will local places like the U-brew you mention keg-up a small batch if you bring in a full, fermented carboy? (I've only done 20-L batches)

I noticed you do roofing. Too bad you're not in the area ;) My house needs some serious attention. I've done a little in the past and I hope I can D-I-'mY' this time too, but time is a big factor. 2 Layers of asphalt to strip first! :gnasher:
ashok
You are all lucky blokes. You can get a whole keg of beer . We can't do that here.
However I make wine . Lots of it because it disappears very fast . I have lots of visitors when there is wine !
I usually make 25 liters at a time and that doesn't last long at all !
Cheers,
Ashok
acoustixman
quote:
However I make wine .

Ashok: Is making wine at all like brewing? As in, do you cook it on the stove to get the sugar out into solution and smell the house up with wonderful aroma (and cover the stove with a sticky mess) for an afternoon, or is it straight to fermenting with the crushed fruits and some added water or so?

I've always wondered if wine-making was another something I could get into. I must need another hobby; all my current projects are about half-done!! :xeye:
Cal Weldon
quote:
Originally posted by acoustixman
Nice setup! So do you give them the recipe and buy the ingredients and they just follow your instructions?

The place I use uses an all-grain kit. Starting with a 15 litre box, they add 8 litres of water and ferment.Take two kits and you have a keg full. They are hesitant about filtering kegging and gassing something not made in-house and I can't say I blame them. Yeast infection is a nasty thing for beer.
quote:
[i]I wouldn't mind discovering how to keg my own stuff up. The biggest brewing prohibitor for me has been bottling. Will local places like the U-brew you mention keg-up a small batch if you bring in a full, fermented carboy? (I've only done 20-L batches) [/B]

Kegging is good. Rather expensive to set up but very convenient and not a whole lot of work. To begin you need a fridge (modified), kegs, taps, fittings, hoses and a CO2 bottle. You also need a welding shop (or WHY) near by to provide the gas, and a U-brew place. Thankfully they are all local for me.
quote:
[i]I noticed you do roofing. Too bad you're not in the area ;) My house needs some serious attention. I've done a little in the past and I hope I can D-I-'mY' this time too, but time is a big factor. 2 Layers of asphalt to strip first! :gnasher: [/B]

I used to roof. I'm an inspector now. The asphalt isn't that hard to strip. Putting the new one back down is when it seems to go slow.
acoustixman
quote:
Originally posted by Cal Weldon
To begin you need a fridge (modified), kegs, taps, fittings, hoses and a CO2 bottle. You also need a welding shop (or WHY) near by to provide the gas, and a U-brew place. Thankfully they are all local for me.

I've got the bev. gas kit (Airgas) and a Sankey tap (hate the idea of air-charging a keg). Only done parties with it - I still need the keg, fridge and a bulkhead shank. I didn't realize I could get a "commercial-style" keg of my own which would be compatible with the standard tap yet contain my own concoctions!
quote:
I used to roof. I'm an inspector now. The asphalt isn't that hard to strip. Putting the new one back down is when it seems to go slow.

What tool(s) make stripping easiest? I used a crowbar last time and it was a !@#$ drag :redhot: - 3 old layers on that roof. Maybe an edger/icebreaker type tool with a shovel-style handle or a square-head shovel could be used in a thrusting manner to get up under the shingles?

I'm thinking I'll just use architectural shingles and only worry about keeping the horizontal lines straight. :smash:
Cal Weldon
quote:
Originally posted by acoustixman
What tool(s) make stripping easiest? I used a crowbar last time and it was a !@#$ drag :redhot: - 3 old layers on that roof. Maybe an edger/icebreaker type tool with a shovel-style handle or a square-head shovel could be used in a thrusting manner to get up under the shingles?

I'm thinking I'll just use architectural shingles and only worry about keeping the horizontal lines straight. :smash:

JW,

Use a long handled spade shovel. You can slide it under and pry up sections at a time.

If you're looking to make it easy, use three tab shingles (unless they don't meet wind uplift ratings). Use a chalk line every few rows to keep your self straight.
ashok
Hi Acoustixman,

Making wine is slightly different from brewing beer. Boiling is used only if we make wine out of vegetables like beetroot , carrots, potatoes etc.
With grapes , pineapples etc , no boiling is required. However everything used is sterile -- rinsed finally in boiled water. The risk of contamination is high and if one is not careful you can end up with 25 liters of wine vinegar !

During the fermentation process ( almost two weeks long ) you will get a 'fermentation smell' through the house. If done in an apartment it will be pretty strong !
Cheers,
Ashok.
classd4sure
Hi,

A normal spade might do but it seems a little weak perhaps? Certainly there's no substitute for the right tool or the proper technique.

Suppose you could always do like the real good contractors and just leave the old ones there.

Might look into a "roof ripper".

Some feature a fulcrum to fascilitate prying (else, use your steel toe under it), serrated edges are great for cutting and prying nails, stronger steel and construction than a typical spade will go a long way too.

Few examples of such here:
http://www.uniontools.com/product.asp?Cid=1&Cat=6

Have FUN! :devilr:
acoustixman
quote:
Originally posted by ashok
if we make wine out of vegetables like beetroot , carrots, potatoes etc.

Far out! I didn't realize that stuff would be even considered for wine! Have you made it out of such veggies with success?!

:cheers:
ashok
Beetroot wine is fabulous. Great aroma and lovely red colour.
Can make it as strong as you want .
Rice wine is also very nice. But I add some green grapes also to give it a better flavour.

Strictly speaking you need yeast meant for brewing wine. That's hard for me to get . So I use normal bakers yeast ( comes in 30gm packets). The yeast affects the final aroma. But I have not had any problems. Maybe the proper yeast will give me a better flavour. In any case what I get is very good , so I am happy.
Cheers,
Ashok.
acoustixman
quote:
Originally posted by Cal Weldon
If you're looking to make it easy, use three tab shingles (unless they don't meet wind uplift ratings). Use a chalk line every few rows to keep your self straight.

We have architecturals now, they seem to lack the requirement of vertical alignment (ugly results if done wrong on 3-tabbers, no?) since the tabs are random and consmetic. That's what I was thinking about. Then again, the 3-tabs are lighter and thinner I think. I'm pretty sure I've seen them in the area and that the wind will be outdone by the sun sticking them down around here...
quote:
Originally posted by classd4sure
Suppose you could always do like the real good contractors and just leave the old ones there.

Not this time. I already have 2 layers up there. I'd probably overload the trusses of this old tract-expansion house, and the new roof wouldn't last any longer than the current, supposed-young one.
quote:
Might look into a "roof ripper".

Some feature a fulcrum to fascilitate prying (else, use your steel toe under it), serrated edges are great for cutting and prying nails, stronger steel and construction than a typical spade will go a long way too.

Few examples of such *snip*...

Have FUN! :devilr:

Thank you very much! I wasn't aware such tools existed. It almost makes it look easy compared to my expectations...

Oh, I'll have fun alright. I am beside myself with excitement about this future project... :cuss: I'm still not completely sure I'll be a DIY on this one. I'll probably at least strip and inspect, but I may then hire someone. Fortunately I've got a little time to think it over since it rarely rains here in the Mojave Desert.

So, are you into class-D for full-range or just subs?
Cal Weldon
Any long handle spade will do. The one classd is describing is used more for tar and gravel roofs where there is more of a prying action and much more weight involved, but it would work well for shingles too.

Only problem is, you can't use it for regular work once the roofing is done.
classd4sure
On the other hand if the point of doing this yourself is some time away from the wife I'd say a few coolers and a spatula are in order.

If you don't get the fulcrum option you can still use it for whatever. My back is sore again just talking about this...

Yes I'm of the belief that class D is not just for subs anymore :)

Cheers,
Chris
acoustixman
quote:
Originally posted by ashok
Beetroot wine is fabulous. Great aroma and lovely red colour.
Can make it as strong as you want. Rice wine is also very nice. But I add some green grapes also to give it a better flavour.

I'll be darned! This bears some exploration (perhaps after my current audio and home-improvement goals are met :rolleyes: )...

Happy listening!
acoustixman
quote:
Originally posted by Cal Weldon
Any long handle spade will do. The one classd is describing is used more for tar and gravel roofs where there is more of a prying action and much more weight involved, but it would work well for shingles too.

Only problem is, you can't use it for regular work once the roofing is done.

Well, I have never regretted the purchase of a tool... ;)
quote:
Originally posted by classd4sure
On the other hand if the point of doing this yourself is some time away from the wife I'd say a few coolers and a spatula are in order.

If you don't get the fulcrum option you can still use it for whatever. My back is sore again just talking about this...

Yes I'm of the belief that class D is not just for subs anymore :)

Well, I'll probably eventually debate you on the class-D thing in the appropriate forum... :D

Gents; thanks for the advice on the re-roof. I'm probably going to procrastinate just a little longer, but It will be coming.

Cal; where'd the duck-avatar go?

By the way... GO BRUINS!! :fight: (I was raised a New Englander!)
Cal Weldon
quote:
Originally posted by acoustixman
Cal; where'd the duck-avatar go?

He had to duck off and head south.

This one is looking inside the mouth of an Altec A7. The driver is a Selenium WPU1507QCF.

Maybe ducky will be back in the summer when it's a little warmer

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