[ting.mike]

So the Beta 22 is still not finished... Initially I wanted to build a 3 boards, but now I pretty much have a balanced source (CEC 5300), a really good balanced interconnect (Transparent Musiclink Plus), and the only thing missing is add one board on the Beta 22, and another sigma board + toroid, and I'll have a sweet balanced set up!

Here's the question though:
On 4 boards Beta22, does that mean that if I run a SE phones, then it's running on 2 boards only (passive ground)? That would suck, wouldn't it?

I thought about it and the solution would be to build a 5 boards Beta22:
1 board - Left +
1 board - Left -
1 board - Right +
1 board - Right -
1 board - Active Ground (SE config)

or.. 6 boards (like outlined in the "options" section of the AMB website)..
but I haven't seen anyone build a 6 board version.. the cost and complexity!

Anyway, I really2 don't want to spend the money for 5 or 6 boards.. and so if I go 4 boards, how bad can the SE out be?
What does other 4 boards user do?


Thanks!

 

[digger945]

Quote:

Originally Posted by ting.mike /img/forum/go_quote.gif .... how bad can the SE out be?

Bad? If you know now that the question will be nagging you until you find out then why don't you go ahead and plan to build the 5 or 6 board amp now.
Then you won't be asking the question in you mind while your listening.

The wiring is NOT that bad. I think if you have come this far you can handle the wiring, no problem.

 

[FallenAngel]

Oh yes, 2 channel unbalanced is absolutely awful, unbearable and almost impossible to listen to, it's a must to go with active ground, and 2 of them so you can drive 2 pairs of headphones using active is absolutely necessary to keep your sanity. If there isn't enough sarcasm in there, let me know, I've got a few more zingers I can add.

 

[Nebby]

Was that sarcasm FallenAngel?

 

[johnwmclean]

ting.mike, the question is how much listening time are you going to devote to SE vs balanced. From the look of your sig going from the number of cans you own I’d say a lot. In your case I’d be looking at a 5 board build for sure.

 

[linuxworks]

since I'm the only person (still living) who owns a 2ch b22, I thought I'd chime in here:

there is some 'overboardedness' so to speak on the # of boards people *think* they need.

my 'lowly' little 2ch b22 still probably can't be audibly told from a 4board system.

if I could setup a blind set of 2 rigs for people to test, I would. I don't believe many people here (if any) could HEAR any diff between them.

feel free to overspend all you want, but its mostly an ego trip - realize that.

2ch is just fine. and mine powers speakers, too, fwiw.

 

[MASantos]

There are quite a few DIY and comercial amplifiers that do not use active ground topologies. The Gilmore amps(considered some of the best DIY amps) Headamp, Headroom, WooAudio, Ray Samuels are a few companies that use passive grounds in some(probably most) of the amps.

So even though I can't comment on a 2 channel B22 because I never heard it, I could assume it won't sound bad at all, and you might even barely hear a difference between a 2channel vs. 3 channel amp.

This said, the good thing about DIY is that you decide what you want and can plan ahead, so if you don't have the $ right now, you can always prepare the casing to support a 5th channel later and add it when you have more available $.

My 0.02€

 

[linuxworks]

when I started out, I bought enough to build a 3board b22.

I stopped at 2 after hearing what it sounded like. it seems to do its job ('driving' the load and keeping the load from driving it)

it is near noiseless and I think its also hum-free (but I need to scope it since there's some background hum in my apartment area that makes 'hearing' hard to tell once you get so close to the noise floor).

now, given that more boards take more power, generate more heat and offer more 'challenges' for grounding and casing, I felt that a 2board 'small b22' (ha!) was a good stopping point. for now, at least.

sure, we can always add more later.

but why not just TRY a smaller config and see if that's ok? why ASSUME 10x overkill when only 5x is needed for overkill (lol).

seriously - look at all the components and space needed for even 'just' a 2board b22. anyone other than people here would think even a 2board b22 is super overkill for 'a phones amp'.

 

[oneplustwo]

Also, you can wire up a 4 channel board to essentially be a three channel config. Amb had posted a schematic about wiring both balanced and SE sources to go with both balanced and SE outputs. I'm in the process of executing that plan myself.

EDIT: Here's the thread that outlines my original plan as well as Amb's alternative which is my new plan.

 

[Ferrari]

Mike, why do you think that 2-channel β22 sucks?

Good designed 2-channel amp can sound very good … that’s my experiences with 2-channel β22 and Dynahi.
Personally, I’m in the process of building a dual 2-channel β22 (balanced) and you guesse why.
(what we call in Dutch: “klein maar fijn” )

 

[aloksatoor]

I like the heatsinks on this one

wot case is it? im planning on building a second 2 ch beta 22 for my workplace

Quote:

Originally Posted by Ferrari /img/forum/go_quote.gif Mike, why do you think that 2-channel β22 sucks? Good designed 2-channel amp can sound very good … that’s my experiences with 2-channel β22 and Dynahi. Personally, I’m in the process of building a dual 2-channel β22 (balanced) and you guesse why. (what we call in Dutch: “klein maar fijn” )

 

[MASantos]

Quote:

Originally Posted by Ferrari /img/forum/go_quote.gif Mike, why do you think that 2-channel β22 sucks? Good designed 2-channel amp can sound very good … that’s my experiences with 2-channel β22 and Dynahi. Personally, I’m in the process of building a dual 2-channel β22 (balanced) and you guesse why. (what we call in Dutch: “klein maar fijn” ) http://i72.photobucket.com/albums/i161/Ferrari_01/DIY/Beta/Afbeelding652.jpg[/IM[/i] [/td] [/tr] [/table] Now where did you get those nice cases from? [img]http://www.head-fi.org/forums/images/smilies/http://hfimage.head-fi.org/smilies/cool.gif

 

[smeggy]

I'm running two boards and it sounds great to my old ears but I've never experienced a balanced version

 

[krmathis]

Quote:

Originally Posted by Ferrari /img/forum/go_quote.gif http://i72.photobucket.com/albums/i161/Ferrari_01/DIY/Beta/Afbeelding652.jpg

Yeah, that is one fine case.
Is it some factory make (brand, model) or a DIY one?

 

[Bullseye]

I have in mind building a B22, but first I need to find the boards and pieces. I am willing to pay an extra for a kit. Anyone knows any site were they sell you a kit (3 - 4 boards, plus material to populate them) and ship it to Europe? Nice one linuxworks.