[Zorander]

Quote:

Originally Posted by johnwmclean /img/forum/go_quote.gif Sigma22? Dual or Single?

I probably will go dual but I would first like to know the total price we will be looking at. My wallet cringes already.

Cheers!

 

[poo]

I'm a DIY moron. There, I said it. Little to no experience, but have been reading and researching since before joining Head-Fi.

In short, I would like 'the best', which is not to say I can afford it (or that 'the best' is necessarily expensive for that matter)... but we all seem to find a way.

I would like a 4-channel "fully balanced" amplifier, and a little guidance from the community along the way please

I plan to integrate this amp into my headphone and speaker systems. Adding it to the headphone gear is simple, but the speaker side of things seems more complex at this point. Currently I drive a 2 ch system via a Musical Fidelity (MF) A3.5 integrated amp. This amp (like many in the range) has a 'HTB' or 'Home Theatre Bypass' feature, which allows the same two speakers from my 2 channel system to be used in my surround system. My simple understanding is that the pre section of the MF 2 ch amp is bypassed when used in HT Bypass mode. Instead, the pre section of my Home Theatre amplifier is used, which is fed to the MF integrated's power section and on to the speakers; the remaining centre and surround speakers are powered directly from the Home Theatre amplifier. I would love to be able to do this whilst introducing a Beta22 in place of the Musical Fidelity amp. I presume I will also need to use a separate power amplifier... Beta24 possibly???

Quote:

Originally Posted by johnwmclean /img/forum/go_quote.gif Also I would strongly recommend the Sigma 22 psu, from what I’ve read it’s the best. For those wishing for balanced, it may me best for Dual Sigma psu’s.

I'm happy with that. Also interested in other suggestions, but my research has also led me to believe it is the best option.

Quote:

Originally Posted by johnwmclean /img/forum/go_quote.gif I’m gonna poke around and see what info I can get for chassis design etc

This is also really important to me. Well worth spending that 'little bit extra' for something aesthetically pleasing... All eye of the beholder stuff, and something we would have to agree on, but I like pretty.

Quote:

Originally Posted by Zorander /img/forum/go_quote.gif I probably will go dual but I would first like to know the total price we will be looking at. My wallet cringes already.

Unfortunate but true... I would also really need a solid expectation of financial commitment up front so I can commit to it.

 

[cotdt]

A balanced Beta22 and a Beta24 is pretty much the same amp except the Beta24 uses even more scaled up parts. The schematics for the two amps look the same except Beta24 is already balanced. I would go with a balanced Beta22 because it uses clean, regulated power supplies (S22). With a few modifications 60W output into 8ohm speakers is no problem. It's not a makeshift speaker amp that is actually a headphone amp, but a high-end speaker amp in its own right.

 

[poo]

Thanks cotdt, I have found your input and cander invaluable while poking around the DIY sections. Would be great if you could keep checking into this thread from time to time and comment!

So I would be fine using a Beta22 to drive floor standers like my Krix Neuphonix? http://www.krix.com/Product/Detail.aspx?p=44&id=1

 

[cotdt]

Quote:

Originally Posted by poo /img/forum/go_quote.gif Thanks cotdt, I have found your input and cander invaluable while poking around the DIY sections. Would be great if you could keep checking into this thread from time to time and comment! So I would be fine using a Beta22 to drive floor standers like my Krix Neuphonix? Krix experience sound - Home Entertainment - Product Detail - Neuphonix

Yeah that speaker uses a Vifa XT25 tweeter and Peerless HDS woofers, the same drivers I've tested the balanced Beta22 with, although my speakers are small bookshelves so they are even less efficient than the Krix Neuphonix. These drivers sound great BTW! As 4 ohm speakers each B22 will see 2 ohms so they really need to be beefed up.

Make sure you use big heatsinks on your Beta22's, as well as your S22's (use one S22 for each B22). The stock PCB heatsinks won't do (tried it, blew up a couple MOSFETs). Those 0.47R resistors should be rated 5W not 2W, or they will blow. You could also turn up the quiescent current, though amb says it's not needed, higher quiescent current has its benefits as you get closer to Class A.

 

[johnwmclean]

Expected wallet damage

, all prices are USD’s. Also note that these are RRP’s and are not discounted as a group buy, it’s just rough at this stage.
Based on the overwhelming popularity of the balanced option prices are based on this configuration.

Balanced kit: $369
Sigma 22 psu kit $104 or $208 for dual

Chassis update:
Based on Krmathis’s Beta22 build $162 (2 cases)
Is Par-Metal 20 series 12x12x3 in clear anodize. Two front panels per case rather than a front and a rear, so that there is a support piece for the rear panel as the fronts.
Let me know if this is sexy enough

I personally love it! See pic.

Also not included in the cost: Connectors, jacks, stepped attenuator, knob, feet, wiring, hardware and myriad other little things which nevertheless add up quickly.

Poo, as you also need to drive speakers expect more damage, going from cotdt’s replies.

 

[johnwmclean]

Quote:

Originally Posted by cotdt /img/forum/go_quote.gif Make sure you use big heatsinks on your Beta22's, as well as your S22's (use one S22 for each B22). The stock PCB heatsinks won't do (tried it, blew up a couple MOSFETs). Those 0.47R resistors should be rated 5W not 2W, or they will blow. You could also turn up the quiescent current, though amb says it's not needed, higher quiescent current has its benefits as you get closer to Class A.

Cotdt, is that 4 x S22’s

Poo have you fainted yet

 

[amb]

Count on spending north of USD$1400 on the total build cost for one similar to the krmathis group-build balanced β22. Your estimate does not include a lot of odds and ends (such as connectors, jacks, stepped attenuator, knob, feet, wiring, hardware and myriad other little things which nevertheless add up quickly). Glassjar's kit does not include these items. The FPE panels alone was $400+ for the krmathis amp.

 

[johnwmclean]

Thanks AMB group for putting things more into prospective

The comments made about the krmathis group build were only referring to the par-metal chassis and not so much to replicate that great amp.

 

[minivan]

if possible,i just want the balanced kits and the sigma kits only,
no chassis please.
i have a bunch of second hand neutrik 3 pin xlr plug, socket ,female
and male type, great for the balance xlr ic cable and xlr connector on chassis. let me know if u guys are interested.

 

[johnwmclean]

Quote:

Originally Posted by minivan /img/forum/go_quote.gif if possible,i just want the balanced kits and the sigma kits only, no chassis please.

Of course, so how handy are you with that soldering iron

I’m interested in the plugs, how many in the bunch?

 

[poo]

Quote:

Originally Posted by johnwmclean /img/forum/go_quote.gif Poo, as you also need to drive speakers expect more damage, going from cotdt’s replies.

Yes... thanks for clarifying that

Quote:

Originally Posted by johnwmclean /img/forum/go_quote.gif Cotdt, is that 4 x S22’s Poo have you fainted yet

Define 'fainted'

I expected substantial pain... and it is being consistently delivered

Can't wait for something to blow up

So long as I end up with an amp that doesn't go destroying itself over time... I guess I'll be happy. Oh... and if it could sound good too... yes, sounding good would be tops!

Now where's that damn Aussie builder gotten to?

 

[poo]

Meant to add, great to have you involved in this thread AMB! Your guidance will obviously be invaluable!

 

[minivan]

Quote:

Originally Posted by johnwmclean /img/forum/go_quote.gif Of course, so how handy are you with that soldering iron I’m interested in the plugs, how many in the bunch?

i have about 10 of each of the 4 diff xlr plug/socket, will keep a pair each for myself and try to get rid all the rest

i found out soldering is the easiest part, testing and trying to figure out what went wrong is the worst part, also casing is hard if u dont have the proper tools

i suggest u guys should all give building the beta 22 yourself a go.
diy may not be as hard as u think. i built myself a buffalo dac and a headamp recently, prior to these, my only experience is some diy calbe, and headphone recabling. so my skills is no diff to u guys.
also diy yourself is fun and rewarding. u get to learn a lot in the process ,nothing beat the feeling of hearing ur own creation sing

ps: does the kits come with the transformer? if it does, better not included , buy local one for the 240v, us use the 220 v ones.

 

[johnwmclean]

Quote:

Originally Posted by minivan /img/forum/go_quote.gif i suggest u guys should all give building the beta 22 yourself a go. diy may not be as hard as u think. i built myself a buffalo dac and a headamp recently, prior to these, my only experience is some diy calbe, and headphone recabling. so my skills is no diff to u guys. also diy yourself is fun and rewarding. u get to learn a lot in the process ,nothing beat the feeling of hearing ur own creation sing ps: does the kits come with the transformer? if it does, better not included , buy local one for the 240v, us use the 220 v ones.

I think it’s highly unlikely that well find a builder

I think your right, DIY should be DIY. Unfortunately this group buy won’t become a reality if there’s no one available to build, as I think everyone here with the exception of yourself need’s it built.

There’s no transformer included as far as I can see, but am confirming this.