[qusp]

just edited my post, read it again. some things are more expensive, you are correct, but some things like the wimas and other bits like the power connectors I linked are cheaper and the best thing is they have EVERYTHING, they carry whole ranges of it all, not just the popular values. If they dont have it in that store, one of them will have it without having to order it from the manufacturer. so it saves money on shipping from different places, because you get it all in the one place. they have spome stuff that you cant really even get almost anywhere else. prices are MUCH better than farnell, only some things are more pricey than digikey, or mouser, but not the wimas and evox films, prices for them are pretty excellent.
 
 
[size=medium]

Farnell are the most expensive supplier of them all and not by a small margin. I have paid 10x more for stuff at farnell

. a common mode choke I needed badly a while ago, just one as I lost one, was `$15 at farnell, 1.40 at mouser 

. Needless to say I only use them if I have to and they got a rude email from me when I saw what they charged me. The 'free shiping' is a farce 

IMO the prices more than cover it, but it IS handy sometimes; to be able to buy a single cap and have it delivered overnight free is pretty cool in a pinch.
​

[/size]

 
oh, BTW, you officially suck having Elfa just up the road
 
sorry for the rant there everyone, touched a nerve 

 

[qusp]

DP

 

[backefel]

Hmm, I probably should have checked with elfa first :/ but like you said it seems to be very dependable on what you buy. I tried to put together a cmoy from elfa, and they wanted 80$ for the parts :S. A small terminal strip cost 4$

.
 
Now that I think about it, it might be store fees or something like that.
 
Haha no problem 

 

[qusp]

well its easy to pay that for a terminal strip if its a high quality one, you may have used the double thick gold plate one or something, as they dont tend to have any of the entry level bulk parts. some things are out of whack and you are better off getting them elsewhere (usually things that are not made in the EU), but since you have them just up the road, taking international shipping into account it would probably still turn out cheaper for just about any BOM, unless large combined one like yours here. Things like SMD resistors are pretty thin on the ground and not great quality. Transistors they have complete ranges of some things, but nothing of others, opamps they are lacking and are pricey for what they do have, dac chips, crystals all of those are expensive or scarce. I tend to get about 50% from digikey, like all transistors, ICs, opamps, dacs, SMD R's and ceramic caps, regular strip connectors etc, then the rest between mouser and elfa. anything specialized like those connectors I get from there and yeah if i'm getting heaps of film caps. any high end build I do will include me begging my mate to make an order for me from there for switches, caps and specialized connectors.
 
anyway i'm raving again, gotta go get some work done, good luck with your project mate!! kudos for building a fully integrated system for yourself, gutsy move. I recently did the same thing (although with a higher budget) as my build to end all builds and i'm just about finished. IMO you can get a much better result when you are able to specifically tune the outputs and inputs to work together, mine ended up outgrowing a single case, due to the rather involved power supply design I went with and 100W heatsinking for my class A mosfet IV stage for the ackodac ;D
 
BTW are you going for digital volume control? I cant remember if they added that to the gamma 2 or not. if you can, I recommend it, reduces costs considerably and IMO makes for better audio too

 

[backefel]

Quote:

well its easy to pay that for a terminal strip if its a high quality one, you may have used the double thick gold plate one or something, as they dont tend to have any of the entry level bulk parts. some things are out of whack and you are better off getting them elsewhere (usually things that are not made in the EU), but since you have them just up the road, taking international shipping into account it would probably still turn out cheaper for just about any BOM, unless large combined one like yours here. Things like SMD resistors are pretty thin on the ground and not great quality. Transistors they have complete ranges of some things, but nothing of others, opamps they are lacking and are pricey for what they do have, dac chips, crystals all of those are expensive or scarce. I tend to get about 50% from digikey, like all transistors, ICs, opamps, dacs, SMD R's and ceramic caps, regular strip connectors etc, then the rest between mouser and elfa. anything specialized like those connectors I get from there and yeah if i'm getting heaps of film caps. any high end build I do will include me begging my mate to make an order for me from there for switches, caps and specialized connectors.
 
anyway i'm raving again, gotta go get some work done, good luck with your project mate!! kudos for building a fully integrated system for yourself, gutsy move. I recently did the same thing (although with a higher budget) as my build to end all builds and i'm just about finished. IMO you can get a much better result when you are able to specifically tune the outputs and inputs to work together, mine ended up outgrowing a single case, due to the rather involved power supply design I went with and 100W heatsinking for my class A mosfet IV stage for the ackodac ;D
 
BTW are you going for digital volume control? I cant remember if they added that to the gamma 2 or not. if you can, I recommend it, reduces costs considerably and IMO makes for better audio too

 

[size=10pt]Oh you might be right, I haven't looked at it myself, but I do remember my dad  saying something about gold plated.[/size]

[size=10pt]I haven't bought any connector yet so I'll skim through the ELFA catalog and see if i can find something nice .[/size]​

 ​

[size=10pt]I was thinking of getting a valab attenuator from ebay but digital might be the way to go. Hmm I wonder if a aurdino based attenuator is the best alternative?[/size]​

 ​

[size=10pt]Haha yeah i saw your QRV-08 in the other thread...good thing this is my first project so I have something to blame the quality/looks on ^^[/size]​

 

[amb]

Quote:

Originally Posted by backefel /img/forum/go_quote.gif
 
These are the ones that weren't in stock btw:
 
MC7815CTG15V Reg1
 
EEU-FC1V221220µF2
 
270-22K-RC22Kohms2
 
TPS79333DBVRReg1
 
270-1K-RC1Kohms1
 
Farnell has all of them (inc. the transfomer for the ck2iii) except for the metal-film resistors from xicon :/

 
Farnell has the Multicomp MF12 series 1/8W resistors which are equivalents to the Xicons. (9342842, 9342400).

 

[qusp]

yeah if you do 2 boxes, definitely check out the amphenol DSUB hybrid power connectors, or even just a chunky high current DSUB blade connector; hell even the quality HD15 dsubs would make for a decent and neat power umbilical. the neutrik powercon connectors are becomiung a bit of a defacto standard there for DC power umbilicals, but I prefer these.
 
the auduino solution on the amb site is a relay based microcontroller controlled attenuator isnt it? thats what I thought. relay based volume controls are very good; the best of the passive resistive types IMO, but i'm talking about a fully digital control, one that uses a microcontroller to interface with the dac chip itself and utilize the internal digital volume. I know the opus was compatible with the volumite, so the WM874X dacs are able to be controlled in this way, but you need a uC (microcontroller) to access the functionality and as AMB hasnt done this for the y2, but has used a uC for other functions, i'm not sure how you would add this. I would maybe ask Ti about it as a really good volume pot can be pricey and this means you can skip that and save or spend the dollars elsewhere. this would mean you dont install a pot in your amps at all, so the input impedance would be totally different and you would probably change the output caps oon the y2 as well.
 
anyway I dont wanna talk too much about it if its not possible.
 
 
 
 

 

[backefel]

You're right I misunderstood the concept of aurdino, it would have been nice option otherwise. I'll post a thread about volumite in the AMB forums tomorrow and check if it's possible to use it with the gamma. Another option (not digital though) would be a lightspeed attenuator...phew, it's good to know that i won't be needing it for three months or so 

.

 

[qusp]

aurduino will actually work to control digital volume via i2c to the wm874X series, but that is not how it is being implemented for the attenuator you are talking about on AMBs site. so you would have to find someone that has written the code and use an Atiny controller or something, connected to the dac chip. not something I would rwecommend to you at this stage. a friend of mine did it with his gamma 2, along with a MUX, I will ask him if you like if it is possible for you to do it

 

[nattonrice]

The gamma2 board would need some surgery to change it to software mode (amongst other things) if you intend to use the volumite.
You could probably use the opus volumite FW with some success.
 
In the end though it'll be a bit of a mess and you may as well just have gotten the opus and volumite.

 

[backefel]

Quote:

 
Farnell has the Multicomp MF12 series 1/8W resistors which are equivalents to the Xicons. (9342842, 9342400).

Sorry I totally missed your post, they would have been perfect but it seems like they are just available through back ordering. So it would add 30$ to the order for just 3 resistors .
 
But it might be possible that I have a few just lying around in my summer house. I should have the correct values but i dont know if it's metal-film or carbon composite. BTW the carbon comp. would add noise right? I might be dependable on the usage..hmm.

 
Quote:

aurduino will actually work to control digital volume via i2c to the wm874X series, but that is not how it is being implemented for the attenuator you are talking about on AMBs site. so you would have to find someone that has written the code and use an Atiny controller or something, connected to the dac chip. not something I would rwecommend to you at this stage. a friend of mine did it with his gamma 2, along with a MUX, I will ask him if you like if it is possible for you to do it

Ah ok ok

! I think I'll have to leave it out this time even though it's very tempting. I don't even know if I will succeed building the two projects or just fail miserably ^^ but thank you anyway. I wouldn't have hesitated if I felt more confident about DIY:ng.

 
Quote:

The gamma2 board would need some surgery to change it to software mode (amongst other things) if you intend to use the volumite.
You could probably use the opus volumite FW with some success.
 
In the end though it'll be a bit of a mess and you may as well just have gotten the opus and volumite.

 
 
Bummer

.
I'm leaning towards copying the layout of the sigma 25 on a weller board (if it's ok with AMB) and use it to drive a lightspeed attenuator.
I don't know if it will be as good as the digital atten. but it is a start and I might be able to upgrade later on.
 

 

[qusp]

I would take the AMB relay based attenuator before the lightspeed. the lightspeed is a good concept, but in reality it adds a not so insignificant amount of distortion and thats if you can get enough matched LDRs. the relay based one (cant remember the project name) is a good design and sound concept, with high performance
 
haha Natonrice, I guess your ears were burning OP this is the guy I was talking about. yeah I would have thought the opus FW would work with a couple changes, not least swapping to software mode, but I dont think its in the scope of the OPs build as you mention. you know me; always trying to ram digital volume down peoples necks I firmly believe its the best option with integrated systems using high enough rez dacs to have enough bandwidth spare for volume control

 

[mattcalf]

Let me know how accurate the BOM turns out, I'm looking to do another order in the next month.
It's much appreciated,
Matt.

 

[backefel]

 
Quote:

I would take the AMB relay based attenuator before the lightspeed. the lightspeed is a good concept, but in reality it adds a not so insignificant amount of distortion and thats if you can get enough matched LDRs. the relay based one (cant remember the project name) is a good design and sound concept, with high performance
 
haha Natonrice, I guess your ears were burning OP this is the guy I was talking about. yeah I would have thought the opus FW would work with a couple changes, not least swapping to software mode, but I dont think its in the scope of the OPs build as you mention. you know me; always trying to ram digital volume down peoples necks I firmly believe its the best option with integrated systems using high enough rez dacs to have enough bandwidth spare for volume control

 
Doh, I thought it was good overall

. The delta-1 looks good (really good) but wouldn't the price be higher than the amp itself? And it still need the LCDuino-1 right? I guess I could stretch a bit though (yes I wont lie, the awsome lcd helps

). BTW The LDR's, costs around 35$ (matched) but with the transformer and sigma25 it would probably reach 60$. Would the 30$ valab attenuator still be a better alternative between the two?
 
Oh ^^. Well I'll leave out the volumite this time, who knows I might upgrade soon anyway . I would just have spammed you guys with low-level questions....not that I aren't already doing it 

 
Quote:

Let me know how accurate the BOM turns out, I'm looking to do another order in the next month.
It's much appreciated,
Matt.

 
Sure, the AMB parts has been shiped and the ones from mouser should be on their way soon as well

.

 

[qusp]

well I bought the PCBs for the lightspeed as well, thinking it sounded like a great idea taking the mechanics out of the signal path etc; but after finding out the distortion specs I decided against it. fair enough for a tube amp that already has a small amount of distortion anyway. Perhaps even any other separate amp that you can have there or not, but for something thats going to be there in the signal path no matter what and on a really tricked out dac aiming to get the best performance possible, it just seemed a bit silly. I mean its not all about the numbers and apparently sounds very well; but when engineering the build to get the best numbers as well as best sound, I didnt feel it was wise.
 
I dont know anything about the valab unit, nah AFAIK you dont need to buy the development kit for the arduino unless you want to mess around with making your own code etc