@Brickj: If your nickname here is derived from your last name, then I did match you and your payment correctly.
But the 'comments' field in PayPal is blank, no name, no address.
Just PM me with your address and everything is golden.
If you intended/tried to send your name, then its okay.
Everybody else is in the spreadsheet.
I'll upload it after the soccer match that just started.
But the 'comments' field in PayPal is blank, no name, no address.
Just PM me with your address and everything is golden.
If you intended/tried to send your name, then its okay.
Everybody else is in the spreadsheet.
I'll upload it after the soccer match that just started.
For those in countries with 220 - 240 VAC line voltage please see post 712 in the PCB Group Buy thread. It appears 12 VAC transformers won't work. I'm revising the BOM and have already revised the O2 Details article.
@All: Please read RocketScientists post in the other thread that he just linked to!
We need a different transformer, as all 12V AC transformers are unlikely to work.
(I sat down in an electronics store and measured every different 12V AC transformer, they all delivered 11,5V@230V from the wall.)
-> The new transformer should have a target voltage of 15V to 18V AC.
Can you please help to look for a reasonably priced transformer I could source?
It would be advantageous NOT to have a 'wall wart' because people could cut the primary cord to replace it with a plug to match the individual need...
Also, if at all possible, I would like to keep it at the current price of 15€...
We need a different transformer, as all 12V AC transformers are unlikely to work.
(I sat down in an electronics store and measured every different 12V AC transformer, they all delivered 11,5V@230V from the wall.)
-> The new transformer should have a target voltage of 15V to 18V AC.
Can you please help to look for a reasonably priced transformer I could source?
It would be advantageous NOT to have a 'wall wart' because people could cut the primary cord to replace it with a plug to match the individual need...
Also, if at all possible, I would like to keep it at the current price of 15€...
Payment sent.
If possible i would like 2 plugs since i'm not sure what plug my transformer has got at the moment (i lost the cable).
The default jack is 2.1mm right? In that case please send 2x 2.5mm jacks as well if it's not to much trouble, just to be on the safe side.
I sent a few extra € hopefully that should cover the plugs/jacks and some extra motivational luxury during the extensive packing...
Thanks for all your hard work.
Edit: I have measured two older 12 VAC transformers around 20VA and both are around 14 VAC without load. So i guess that you need to measure each individual transformer to know for certain.
If possible i would like 2 plugs since i'm not sure what plug my transformer has got at the moment (i lost the cable).
The default jack is 2.1mm right? In that case please send 2x 2.5mm jacks as well if it's not to much trouble, just to be on the safe side.
I sent a few extra € hopefully that should cover the plugs/jacks and some extra motivational luxury during the extensive packing...
Thanks for all your hard work.
Edit: I have measured two older 12 VAC transformers around 20VA and both are around 14 VAC without load. So i guess that you need to measure each individual transformer to know for certain.
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Most trafos I measure will inevitably deliver higher voltage than targeted with no load. In fact, I can't see what kind of transformer won't do that. Smaller transformers have larger regulation percentages as well, so a small 12V trafo can easily deliver 18V unloaded, I've got a few of those.
That makes me wonder - why the difference? Because they're rated for 240/12, while line tolerances can bring yours down to 210? Still, unloaded of 11VAC would imply extremely tight regulation. I guess they're good trafos, after all?
In hindsight, 15V would be a safer choice.
That makes me wonder - why the difference? Because they're rated for 240/12, while line tolerances can bring yours down to 210? Still, unloaded of 11VAC would imply extremely tight regulation. I guess they're good trafos, after all?
In hindsight, 15V would be a safer choice.
I had measured the line voltage: 230,5V. Clean and green as it comes...
I guess it might be because most of those transformers are rated for 240V AND illumination purposes.
(Small 12V bulbs would burn out faster if they were fed more than 12V...)
As I said, I invite anybody to help me find a suitable replacement.
I guess it might be because most of those transformers are rated for 240V AND illumination purposes.
(Small 12V bulbs would burn out faster if they were fed more than 12V...)
As I said, I invite anybody to help me find a suitable replacement.
I'm getting these :
NEW AC-AC TRANSFORMER MAINS ADAPTOR 240V TO 16V 700 ma | eBay
Only good for people in the UK, HK and SG.
NEW AC-AC TRANSFORMER MAINS ADAPTOR 240V TO 16V 700 ma | eBay
Only good for people in the UK, HK and SG.
The Motorola regulators reach their drop out voltage at about 11.5 VAC loaded. If the amp is driving a low impedance load at high current levels, you need at least 12 VAC loaded. Given the variations in line voltage, a 14 - 18 VAC transformer is indeed the safer choice.
A group buy of the Stontronics AC-1550 would be a great solution. I'm also sure there are Asian sources that would be even cheaper if someone can find one willing to sell in the right quantities (or offer them on eBay etc.).
16 VAC is common for alarm systems but most of those transformers are sold with either screw terminals at the transformer or bare wire leads.
It's also worth noting the PSRR of the O2 is so high, even with LOTS of ripple on the rails with the regulators operating well below their drop out voltage, the dScope measurements only change slightly. Put another way, the ripple/loss of regulation is very likely inaudible.
Even with sensitive headphones you can plug the AC power into the O2 at full volume with nothing playing and there isn't so much as a "tick" in the heapdhones. The rails are jumping from +/- 9 volts to +/- 12 volts which would create an output transient in many discrete amps, but the PSRR of the op amps is so high in the O2 the change is inaudible. The same is true when you unplug the AC power and the rails drop back to 9 volts.
A group buy of the Stontronics AC-1550 would be a great solution. I'm also sure there are Asian sources that would be even cheaper if someone can find one willing to sell in the right quantities (or offer them on eBay etc.).
16 VAC is common for alarm systems but most of those transformers are sold with either screw terminals at the transformer or bare wire leads.
It's also worth noting the PSRR of the O2 is so high, even with LOTS of ripple on the rails with the regulators operating well below their drop out voltage, the dScope measurements only change slightly. Put another way, the ripple/loss of regulation is very likely inaudible.
Even with sensitive headphones you can plug the AC power into the O2 at full volume with nothing playing and there isn't so much as a "tick" in the heapdhones. The rails are jumping from +/- 9 volts to +/- 12 volts which would create an output transient in many discrete amps, but the PSRR of the op amps is so high in the O2 the change is inaudible. The same is true when you unplug the AC power and the rails drop back to 9 volts.
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@Atilla: That's the kind I had until now.
I specifically chose them because they either work with the existing plug, or UK guys could cut the cord and use a different plug...
I'll ask the manufacturer of the 11.5V units if they would make a custom production run for us.
Don't worry, we WILL have a good transformer!
I specifically chose them because they either work with the existing plug, or UK guys could cut the cord and use a different plug...
I'll ask the manufacturer of the 11.5V units if they would make a custom production run for us.
Don't worry, we WILL have a good transformer!
Jokener,
I was distracted by the football match and forgot to put my diyaudio name in the paypal notes. Paid 21,53: email address joshcarpenter64@hotmail.com
Sorry about the hassle.
I was distracted by the football match and forgot to put my diyaudio name in the paypal notes. Paid 21,53: email address joshcarpenter64@hotmail.com
Sorry about the hassle.
Hi Jokener, I would like my order to be:-
2 no. kits
2 no. b2 cases, one black, one blue
When I asked about the end caps I had looked on RS BOM where they were priced at $6.82. I have since looked on Farnells site and as you say they are 29 euro.
If , as you think, Farnell have made a mistake and they should be priced around 7 or 8 euro I don't mind sharing the 20 euro shipping cost and I would like one black pair for the b2 enclosure.
If the price is still 29 euro I would not want them thanks.
Extras:-
2 no. red buttons 611-G003R
2 no. grey buttons 611-G003G
1 no. knob white line 450-BA761
1 no. knob red line 450-BA161
2 no. phone jacks black STX-3120-5B
2 no. phone jacks green STX-3120-5B-577C
2 no. ALPS pots with 15A taper
1 no. 60/40 solder
1 no. desolder wick braid
Final order!
Many thanks
2 no. kits
2 no. b2 cases, one black, one blue
When I asked about the end caps I had looked on RS BOM where they were priced at $6.82. I have since looked on Farnells site and as you say they are 29 euro.
If , as you think, Farnell have made a mistake and they should be priced around 7 or 8 euro I don't mind sharing the 20 euro shipping cost and I would like one black pair for the b2 enclosure.
If the price is still 29 euro I would not want them thanks.
Extras:-
2 no. red buttons 611-G003R
2 no. grey buttons 611-G003G
1 no. knob white line 450-BA761
1 no. knob red line 450-BA161
2 no. phone jacks black STX-3120-5B
2 no. phone jacks green STX-3120-5B-577C
2 no. ALPS pots with 15A taper
1 no. 60/40 solder
1 no. desolder wick braid
Final order!
Many thanks
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