hello
I need to have suggestions for standard rack mount and table top enclosures manufacturers for hifi and Pro audio projects.
I used to order Sescom chassis. Not bad but something different would be appreciated.
Thanks
Luke
I need to have suggestions for standard rack mount and table top enclosures manufacturers for hifi and Pro audio projects.
I used to order Sescom chassis. Not bad but something different would be appreciated.
Thanks
Luke
Luke123:
I recently built an amp into a Lansing B-style Graybox. They are beautiful extruded aluminum components. The structure is the most intuitive I have seen (side panels dominant (and thick!), front and back between, top and bottom last). The front, back, and side panels have internal "lips" top and bottom which can be used as I did to mount a very strong internal skeleton. It's like a brick outhouse, and without all the corner pieces and small hardware you sometimes see (8 screws hold it, before rack-mount ears are placed.
They have shielding, venting, internal PCB guide, and color options, and the B-style is certainly not their only offering. It is however the one I will use for my next project.
The website:
http://www.lansing-enclosures.com/siteatlas/
Happy constructing!
I recently built an amp into a Lansing B-style Graybox. They are beautiful extruded aluminum components. The structure is the most intuitive I have seen (side panels dominant (and thick!), front and back between, top and bottom last). The front, back, and side panels have internal "lips" top and bottom which can be used as I did to mount a very strong internal skeleton. It's like a brick outhouse, and without all the corner pieces and small hardware you sometimes see (8 screws hold it, before rack-mount ears are placed.
They have shielding, venting, internal PCB guide, and color options, and the B-style is certainly not their only offering. It is however the one I will use for my next project.
The website:
http://www.lansing-enclosures.com/siteatlas/
Happy constructing!
Acoustixman
Wowww!
Thanks for the cue!
In fact it is a beautiful line and I think much better thant the Sescom line I used to buy. Looks so versatile. Intelligent features.
But in term of built quality and overall finish, how does it compare to Sescom? Much better?
Luke123
Wowww!
Thanks for the cue!
In fact it is a beautiful line and I think much better thant the Sescom line I used to buy. Looks so versatile. Intelligent features.
But in term of built quality and overall finish, how does it compare to Sescom? Much better?
Luke123
Luke123 said:
Luke, to be perfectly honest with you I have never used any kits besides the black-anodized Graybox-B. The anodizing is as good as I've seen; consistent even finish... The surface of the extruded parts has bits of "brushed-look" extrusion artifacts (makes more noise with fingernail dragging across than lengthwise if you know what I mean). I personally favor that appearance; looks sort of industrial. All blemishes in this project were caused by ME. 🙄 It's a prototype...
For fit, the chassis can't be beat. The actual dimensions are perfect. My measurement of the parts before setting about milling my internal framework was unnecessary; the specifications were abided to a T by their production. The front and rear panels are identical, and they contain extrusion guides which are tapped for the assembly screws. The side panels mount upon the front/rear, and the screws are countersunk. The alignment is excellent. When I got the box out of the shipping box, I of course put it together. It assumes perfectly flat (4-point) stance on known flat bench top. All I had to do to get it to full strength was install 8 screws, 2 per corner, and tighten.
My favorite part is the L-angle extrusion inside top and bottom perimeter (provides mounting surface for top/bottom yet also internal structural bearing.
The only complaint I have is that the top and bottom panels (sheet / not extrusion) are drilled slightly off so that the countersink screws there can't all center at once. The top and bottom panels have the least dominance (strength is almost completely provided by sides and front/rear, even most of "footprint parallelogram" rigidity) so this is not a big deal for me. The top and bottom mount to an inset area created by the front/rear/side extrusions and are not part of the footprint if that is a good visualization.
Zis help?? I'll try to get you a couple close-ups, but our digital camera is busy at the moment...
OK here we go... This should give a good idea of how the panels assemble and the internal structure flexibility you have with these boxes... Hopefully you can also see the surface finish a bit... This is my first photo upload... bear with me... May have to edit.
Like I said the nix in the finish are my own...
Like I said the nix in the finish are my own...
Attachments
Acoustixman
Thanks for the photos.
In fact the chassis really looks seriously built.
Nice product for the money.
But about your amp, tell me more about it. It seems to be a long time job!
Luke
Thanks for the photos.
In fact the chassis really looks seriously built.
Nice product for the money.
But about your amp, tell me more about it. It seems to be a long time job!
Luke
Luke;
I guess I took this project pretty seriously. It was about 5 months start to finish, partly spent designing and rounding up parts, partly laying out PCBs, partly revising concept and redesigning PCBs...
It's pretty strong; the internals include about 12 feet of 3/4x1/2" 6063 Alum channel (1/8" thick), so at 14.5 kilos it should be mostly OK if it gets dropped from torso height, but I'm not about to do it on purpose.
Key topology influences have been W.M.Leach; low TIM amp,
http://users.ece.gatech.edu/~mleach/lowtim/,
and G.R.Slone's High Power Audio Amplifier Construction Manual (sorry no link but found on http://www.amazon.com/), but I have made some divergences from both. Description OK? So far I know where all copies of the schematic are... I'm still a little afraid to freely distribute it... I promise I'm not trying to be pretentious...
PS: 750VA Plitron toroid (very quiet!), 35A bridge, 2x 37,000uF caps...+/-70V rails... I pull air through with 24VDC fan in rear on aux. reg. power supply, speed is a function of interior temperature.
Amp (x2): Comp-sym (mirrored) quad-cascoded diff in front -> high-beta (non-darlington) mirrored cascoded VA stage with mirrored 2-pole compensation -> BJT class-A EF buffers -> 2x parallelled LMOSFET (TO-3) class-B SF outputs...
Not quite sure of open-loop gain. Moderate degenerative FB provided throughout; (semi-) global FB includes 2x 22pF roll-off direct from VA output + HF control FB from buffers + audio band FB from FETs. +34dB closed-loop. DC coupling throughout - I like to live dangerously (DC-sensing speaker protection included however)!
Class-B biasing turns out pretty easy and clean with Lateral FETs (thermal tracking not necessary) and idles very cool. Most importantly, I am thoroughly pleased with the sound. Transient delivery is crispy! The 2-pole compensation + cascodes on all gain components seem to make it very quick. I'd like to think it's just the right compromise between Hi-Fi and Pro-sound, but of course I am 'biased'... 😀
What about your projects?
I guess I took this project pretty seriously. It was about 5 months start to finish, partly spent designing and rounding up parts, partly laying out PCBs, partly revising concept and redesigning PCBs...
It's pretty strong; the internals include about 12 feet of 3/4x1/2" 6063 Alum channel (1/8" thick), so at 14.5 kilos it should be mostly OK if it gets dropped from torso height, but I'm not about to do it on purpose.
Key topology influences have been W.M.Leach; low TIM amp,
http://users.ece.gatech.edu/~mleach/lowtim/,
and G.R.Slone's High Power Audio Amplifier Construction Manual (sorry no link but found on http://www.amazon.com/), but I have made some divergences from both. Description OK? So far I know where all copies of the schematic are... I'm still a little afraid to freely distribute it... I promise I'm not trying to be pretentious...
PS: 750VA Plitron toroid (very quiet!), 35A bridge, 2x 37,000uF caps...+/-70V rails... I pull air through with 24VDC fan in rear on aux. reg. power supply, speed is a function of interior temperature.
Amp (x2): Comp-sym (mirrored) quad-cascoded diff in front -> high-beta (non-darlington) mirrored cascoded VA stage with mirrored 2-pole compensation -> BJT class-A EF buffers -> 2x parallelled LMOSFET (TO-3) class-B SF outputs...
Not quite sure of open-loop gain. Moderate degenerative FB provided throughout; (semi-) global FB includes 2x 22pF roll-off direct from VA output + HF control FB from buffers + audio band FB from FETs. +34dB closed-loop. DC coupling throughout - I like to live dangerously (DC-sensing speaker protection included however)!
Class-B biasing turns out pretty easy and clean with Lateral FETs (thermal tracking not necessary) and idles very cool. Most importantly, I am thoroughly pleased with the sound. Transient delivery is crispy! The 2-pole compensation + cascodes on all gain components seem to make it very quick. I'd like to think it's just the right compromise between Hi-Fi and Pro-sound, but of course I am 'biased'... 😀
What about your projects?
Acoustixman
I was looking for electronic enclosure alternative because I needed something flashier than the usual Sescoms I use for projects.
Mostly chosen for my Lab's custom test gears and pro-audio custom projects.
My next project is an electronic dedicated analog crossover/Preamp for my next 3 way system.
Luke
I was looking for electronic enclosure alternative because I needed something flashier than the usual Sescoms I use for projects.
Mostly chosen for my Lab's custom test gears and pro-audio custom projects.
My next project is an electronic dedicated analog crossover/Preamp for my next 3 way system.
Luke
Luke;
Sweet (on the Pre/XO plans)! I have recently been trying to set about designing a similar appliance... My amp is without permanent access to my listening system since it wants to replace a pretty well-featured audio receiver and my wife likes the remote control... my amp can't be turned down without walking over to it. Of course, an active XO means I need 2 more power units... 🙂
I'm trying to figure out how rigorously to approach a pre-amp design... I was thinking of using Lin-3/mirror-image topology and low open-loop gain for about 6dB closed... I'm just thinking people use good op-amps for lots of simple tasks, so why not use Lin 3-stage in a pre-amp? ...then again maybe it's too complex to be sensible if very little voltage gain is being done.
What sort of power supply and control section (s.sel / volume / etc.) are you using for your pre-amps? Are you including tone controls and/or balanced XLR inputs? Cartridge capability?
By the way I am definitely going to keep using Lansing boxes (not only because I want everything to look similar); they rock (in the passive sense)! 😀
Sweet (on the Pre/XO plans)! I have recently been trying to set about designing a similar appliance... My amp is without permanent access to my listening system since it wants to replace a pretty well-featured audio receiver and my wife likes the remote control... my amp can't be turned down without walking over to it. Of course, an active XO means I need 2 more power units... 🙂
I'm trying to figure out how rigorously to approach a pre-amp design... I was thinking of using Lin-3/mirror-image topology and low open-loop gain for about 6dB closed... I'm just thinking people use good op-amps for lots of simple tasks, so why not use Lin 3-stage in a pre-amp? ...then again maybe it's too complex to be sensible if very little voltage gain is being done.
What sort of power supply and control section (s.sel / volume / etc.) are you using for your pre-amps? Are you including tone controls and/or balanced XLR inputs? Cartridge capability?
By the way I am definitely going to keep using Lansing boxes (not only because I want everything to look similar); they rock (in the passive sense)! 😀
Acoustixman
I'll come back on the preamp subject in a next post.
I'm too rushed right now...
But I also discovered Par-Metal products.
Did you ever ordered these? Any comment if so?
Luke
I'll come back on the preamp subject in a next post.
I'm too rushed right now...
But I also discovered Par-Metal products.
Did you ever ordered these? Any comment if so?
Luke
Yes they are chassis enclosures.
http://www.par-metal.com/
Look at the affordable 10 and 20 series and the table top 20 series.
They look good...at least for the price.
Maybe not as sophisticated as Lansing but nice enough to give a try...
Luke
http://www.par-metal.com/
Look at the affordable 10 and 20 series and the table top 20 series.
They look good...at least for the price.
Maybe not as sophisticated as Lansing but nice enough to give a try...
Luke
I have several here, that I bought either through group buys or from another person. They are quite nice looking, at least to me, and quite reasonably priced. I ordered a Par Metals 20 series 16x12x3 in black anodize from Par Metals a week ago, with an internal divider plate, no front panel (going to use Front Panels Express). The cost was about $70+ship for that case; not getting the front panel only saved $9, and the divider added $13. Now, the big problem with them is they are slow, and have reliability problems. I know several people who have ordered from them, it takes 2-3 weeks to get the case, some have gotten their orders messed up, and at least one I know of ordered 5 weeks ago, called at 4 weeks, only to find they had no record of the order, so had to replace the order. Fortunatly, they bill when the case actually ships, but there are some issues. Barring that, they are quite nice, I havnt actually used mine yet, waiting on parts and such, as well as projects for some of them.Luke123 said:
Cetoole
Not very encouraging. It seems to be hard to get a "globally" good product. I was kind of attracted by Par-Metal also.
I used to buy from Sescom for twenty years but something changed since few years. It is not that they are not honest. They are nice people but they will have to change few things if they want to keep their customers. Apart from their poor packing practices which creates scratches and bents on their products, you buy at U$50 and at the end it comes to you at $120CAN believe it or not!!! UPS alone costs you more than $60CAN for their overall services.
Overpriced duties fees and others discourage anybody from buying american. I don't know if the free trade people in US are awared of that since it is unfair "rules and politics" from the Canadian government that produces this situation that companies like UPS exploit in an un-honest way.
Just do a google search with <UPS brokerage fees> and be prepared to laugh.
Anyway...I'll calm myself!
At least Lansing seems to be a decent product.
Thanks for the cue, Cetoole.
Luc
Not very encouraging. It seems to be hard to get a "globally" good product. I was kind of attracted by Par-Metal also.
I used to buy from Sescom for twenty years but something changed since few years. It is not that they are not honest. They are nice people but they will have to change few things if they want to keep their customers. Apart from their poor packing practices which creates scratches and bents on their products, you buy at U$50 and at the end it comes to you at $120CAN believe it or not!!! UPS alone costs you more than $60CAN for their overall services.
Overpriced duties fees and others discourage anybody from buying american. I don't know if the free trade people in US are awared of that since it is unfair "rules and politics" from the Canadian government that produces this situation that companies like UPS exploit in an un-honest way.
Just do a google search with <UPS brokerage fees> and be prepared to laugh.
Anyway...I'll calm myself!
At least Lansing seems to be a decent product.
Thanks for the cue, Cetoole.
Luc
Acoustixman
The next project I have in mind...
The enclosures are built since 6 months. Transducers chosen. And I' m ready to load them as soon as I have the money to do it!
This system is a 3 way using one Bryston 4B for lows, one Bryston 3B for mids and a McIntosh MC502 for highs.
The future preamp will be made of a single 10-12dB gain stage only with a Burr-Brown OPA627 in each channel. Possibly with a servo stage.
The chassis will also house the dedicated crossover units for processing. All filters in each band are custon designed to produce desired specific acoustic transfer functions on each driver. No textbook crossover here.
All filters used will be GIC types. Only all-pass filters will retain the usual Sallen-key topology...but this could change maybe.
PSU will be outboard probably and will be designed for at least three times the current demand as overkill. I like relaxed and very clean supplies!
The retained regulators section will be a serial pair of National LM350.
Simple preamp with a volume control, source selector, few internal features like LF section dedicated peak limiters, internal gain control for overall future set-ups.
A selector for direct crossover input for a future custom made 5.1 preamp that will redirect its L&R outputs to this input.
No subs needed as the basic stereo system has a pair of subwoofers.
A lot of planning for the future.
By the way what do you mean by <Lin-3/mirror topology> ?
I just don't come often in audio forums...
Luke
The next project I have in mind...
The enclosures are built since 6 months. Transducers chosen. And I' m ready to load them as soon as I have the money to do it!
This system is a 3 way using one Bryston 4B for lows, one Bryston 3B for mids and a McIntosh MC502 for highs.
The future preamp will be made of a single 10-12dB gain stage only with a Burr-Brown OPA627 in each channel. Possibly with a servo stage.
The chassis will also house the dedicated crossover units for processing. All filters in each band are custon designed to produce desired specific acoustic transfer functions on each driver. No textbook crossover here.
All filters used will be GIC types. Only all-pass filters will retain the usual Sallen-key topology...but this could change maybe.
PSU will be outboard probably and will be designed for at least three times the current demand as overkill. I like relaxed and very clean supplies!
The retained regulators section will be a serial pair of National LM350.
Simple preamp with a volume control, source selector, few internal features like LF section dedicated peak limiters, internal gain control for overall future set-ups.
A selector for direct crossover input for a future custom made 5.1 preamp that will redirect its L&R outputs to this input.
No subs needed as the basic stereo system has a pair of subwoofers.
A lot of planning for the future.
By the way what do you mean by <Lin-3/mirror topology> ?
I just don't come often in audio forums...
Luke
Luke123 said:
Hmmm... sounds effective... Slick op-amps! I hadn't seen them B4.
GIC??
Amen!! 😎
Very agreeable. 😎
Lin-3-stage: conventional audio [power] amplifier layout:
stage 1: differential / error amp / comparator input
stage 2: voltage amplifier / transimpedance section
stage 3: voltage follower / current boost / buffer / predriver
Mirror or complementary symmetry topology:
Everywhere an NPN transistor exists relative to one power supply rail, a PNP transistor exists relative to the other, and so on; balanced tension everywhere. There are 2 of everything in each of the 3 above stages... 😉 I'm thinking of using this rather power-amp-oriented approach for my future pre-amp (just with lower gain and reduced power output capability), and am mostly wondering how odd that would make me. 😀
Luke, are you interested in these at all?:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=75036
http://www.diyaudio.com/forums/showthread.php?s=&threadid=75036
Acoustixman
GIC stands for generalized immittance converter or generalized impedance convertee as some calls them.
Here is a picture of a typical 4th order high-pass filter.
http://img202.imageshack.us/img202/6522/gichpf43bn.png
I'll make a search through this forum for your preamp topology. Seems interesting...very interesting.
By the way did you have a look at cheeba's chassis website?
Totally freakin on this! :
http://www.atiresearch-anodized.com/products.html
Luke
GIC stands for generalized immittance converter or generalized impedance convertee as some calls them.
Here is a picture of a typical 4th order high-pass filter.
http://img202.imageshack.us/img202/6522/gichpf43bn.png
I'll make a search through this forum for your preamp topology. Seems interesting...very interesting.
By the way did you have a look at cheeba's chassis website?
Totally freakin on this! :
http://www.atiresearch-anodized.com/products.html
Luke
Luke:
GIC: Quite the rigorous filter topology!! I'll have to study this a bit...
ATI chassis: WOW. These are beautiful! I had never seen any quite like this before. I can visualize valve monoblox (and more) looking very pretty in these ATI ones... Thanks for the links!
I've done a little searching for a pre-amp topology like mine but I haven't turn up any matches...could be missing on a keyword or something. I was thinking of investigating preamp recommendations of mirrored Lin-3 power amp proponents like Leach and Slone...
GIC: Quite the rigorous filter topology!! I'll have to study this a bit...
ATI chassis: WOW. These are beautiful! I had never seen any quite like this before. I can visualize valve monoblox (and more) looking very pretty in these ATI ones... Thanks for the links!
I've done a little searching for a pre-amp topology like mine but I haven't turn up any matches...could be missing on a keyword or something. I was thinking of investigating preamp recommendations of mirrored Lin-3 power amp proponents like Leach and Slone...
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