I know futurlec has offices in Australia, but I am not sure if they ship from there:
Futurlec
2 / 136 Broadmeadow Rd,
Broadmeadow,
NSW 2292
Australia
Fax No.: 02 49 62 3231
Futurlec
2 / 136 Broadmeadow Rd,
Broadmeadow,
NSW 2292
Australia
Fax No.: 02 49 62 3231
Checked out Futurlec Aust. They have National Semi. LM318N in stock for AU $1.00.
So sourcing problem solved, lumumba_p.
Hope that is the problem, and nothing simpler. Would need to be common to all three boards, since the same problem exists in all three, as I understand you.
They do not even list the National LM 3886TF, only the uninsulated LM3886T.
Audie.
So sourcing problem solved, lumumba_p.
Hope that is the problem, and nothing simpler. Would need to be common to all three boards, since the same problem exists in all three, as I understand you.
They do not even list the National LM 3886TF, only the uninsulated LM3886T.
Audie.
I have dealt with Futurlec, and they do have Aussie contact details, but the packages I received always came from Asia - Thailand, I think.
Michael
Michael
Re: Re: Re: Heat Generation
I am happy with Adobe photoshop CS2.. Let you do absolutely anything even remove high spot lighting created by flash.. Or ajust background lf foreground is too bright.. The end result? Perfect picture from a 'not so good one'..
Cheers
Henri
🙂
jaudio said:
I am happy with Adobe photoshop CS2.. Let you do absolutely anything even remove high spot lighting created by flash.. Or ajust background lf foreground is too bright.. The end result? Perfect picture from a 'not so good one'..
Cheers
Henri
🙂
Hi,
Spent some time listening to the My Ref C.
The amp worked perfectly. No unwanted noise detectable. Confirms the very low signal to noise performance claim.
As a precaution, I connected a quality speaker protector which I set to trip at 60 watts.
I could get the protector to trip on some music peaks at excessively loud volumes, in my large living room. These were sound volumes that a deaf person would not listen at.
Setting the protector to 80 watts prevented further trips at the same loudness.
The interesting thing is that the amplifier did not audibly clip, as some people have reported.
My speakers are hi-end large full-range floorstanders with 90db efficiency.
They have a nominal impedence of 4ohm. But for a dip to 3ohm at 100 hz, the impedance would be 6 to 8 ohm.
The sound was everything, and more, than I expected. After 40 hours burn-in load, I could not detect any sound abberations.
I won't go into detail, but I would suggest that the amp is a great bargain,and would be the perfect component to build a hi-end fi-fi system around. It is very revealing of the quality of the source components,and recording quality ( assuming the speakers are of sufficient quality).
I am not a fan of CD but The My Ref made the experience enjoyable, especially using a good quality valve preamp.
Vinyl records were very natural sounding.
I will not be selling my valve amps, but the My Ref C will be a valued part of my system, and will see frequent use.
Audie.
Spent some time listening to the My Ref C.
The amp worked perfectly. No unwanted noise detectable. Confirms the very low signal to noise performance claim.
As a precaution, I connected a quality speaker protector which I set to trip at 60 watts.
I could get the protector to trip on some music peaks at excessively loud volumes, in my large living room. These were sound volumes that a deaf person would not listen at.
Setting the protector to 80 watts prevented further trips at the same loudness.
The interesting thing is that the amplifier did not audibly clip, as some people have reported.
My speakers are hi-end large full-range floorstanders with 90db efficiency.
They have a nominal impedence of 4ohm. But for a dip to 3ohm at 100 hz, the impedance would be 6 to 8 ohm.
The sound was everything, and more, than I expected. After 40 hours burn-in load, I could not detect any sound abberations.
I won't go into detail, but I would suggest that the amp is a great bargain,and would be the perfect component to build a hi-end fi-fi system around. It is very revealing of the quality of the source components,and recording quality ( assuming the speakers are of sufficient quality).
I am not a fan of CD but The My Ref made the experience enjoyable, especially using a good quality valve preamp.
Vinyl records were very natural sounding.
I will not be selling my valve amps, but the My Ref C will be a valued part of my system, and will see frequent use.
Audie.
This reminds me a of story I was telling Russ. I was listening to my RevC on the workbench (no case, workbench speakers) while working. I heard this strange buzzing coming from my speakers from time to time. I looked everything over, but nothing seemed out of place.
I had just shipped a bunch of kits, and started to panic that there was some flaw in the kits. After about another 30 minutes of tracking, I found it was fret buzz, recorded in the track. Just hadn't noticed it before. DOH!
Beer and trouble shooting don't mix...
I had just shipped a bunch of kits, and started to panic that there was some flaw in the kits. After about another 30 minutes of tracking, I found it was fret buzz, recorded in the track. Just hadn't noticed it before. DOH!
Beer and trouble shooting don't mix...
BrianDonegan said:
😀
I was a victim of a fret buzz when first time testing my rev_a, listening Jimi Hendrix.I started to punic to, until i played another cd. That cd was one of the most pleasant hearing i had in my life😎
Thanks evryone.
I have ordered LM318N from Futurlec and waiting to see if that will fix my problems. And again - the strangest thing is that my amps are working, there is no noize or DC offsets, and the sound is clean, but LM318H are hot! I did not run it for a long time.
I have ordered LM318N from Futurlec and waiting to see if that will fix my problems. And again - the strangest thing is that my amps are working, there is no noize or DC offsets, and the sound is clean, but LM318H are hot! I did not run it for a long time.
Hi lumumba_p,
I would think the temperatures you reported for the LM318 are excessive.
Though the amp appears to be working ok, the concern would be that if the chip breaks down it will also take out something else with it.
Best of luck.
Audie.
I would think the temperatures you reported for the LM318 are excessive.
Though the amp appears to be working ok, the concern would be that if the chip breaks down it will also take out something else with it.
Best of luck.
Audie.
BoM help
Hi,
I'm planning to build a 5 channel MyRef_C amp. The PCBs will be etched locally by a friend. I'm now trying to build a correct BoM from what I read in this thread, based on the original BoM that Brian posted. I've put the parts, trafos, chassis, etc to get a precise idea of the total cost. Each part has a Farnell or RS code, since that's where I'll be ordering.
For some parts I couldn't find an exact equivalent or I'm not sure about it. These are marked in orange in the Excel file.
- The rectifier bridges : would this be OK ?
- C15 (22uf 50V EL) : I have no idea what to use instead of the Nichicons. Any suggestions in the RS catalog ? 440-6474 maybe ?
- C30 (1nf 100V) : couldn't find any with these specs
- C32 (150pf 200V) : would RS #2508854877 be OK ?
- Mains inlet : Is the part I chose overkill ?
- Fuses : what fuses should I use ?
- Signal wire : what gauge should these be ?
- Case : is RS#224-420 Ok ?
Could you help me finish this ? I'm definitely a beginner and I need some advice before I run the orders.
Thanks in advance,
Julien
Hi,
I'm planning to build a 5 channel MyRef_C amp. The PCBs will be etched locally by a friend. I'm now trying to build a correct BoM from what I read in this thread, based on the original BoM that Brian posted. I've put the parts, trafos, chassis, etc to get a precise idea of the total cost. Each part has a Farnell or RS code, since that's where I'll be ordering.
For some parts I couldn't find an exact equivalent or I'm not sure about it. These are marked in orange in the Excel file.
- The rectifier bridges : would this be OK ?
- C15 (22uf 50V EL) : I have no idea what to use instead of the Nichicons. Any suggestions in the RS catalog ? 440-6474 maybe ?
- C30 (1nf 100V) : couldn't find any with these specs
- C32 (150pf 200V) : would RS #2508854877 be OK ?
- Mains inlet : Is the part I chose overkill ?
- Fuses : what fuses should I use ?
- Signal wire : what gauge should these be ?
- Case : is RS#224-420 Ok ?
Could you help me finish this ? I'm definitely a beginner and I need some advice before I run the orders.
Thanks in advance,
Julien
I can't find that 150pf cap in RS, prefferably it wil be a COG type...
As for the 22u one you pcked... you have to buy 50 at a time... why not look at 215-5758
As for the 22u one you pcked... you have to buy 50 at a time... why not look at 215-5758
You can use just about any 22uF 50V cap, it's just part of the RC timer for the relay, and has no effect on the sound.
That bridge looks fine.
Send me an email if you can't find anything. We are switching our kits over to Silver Micas for the pf caps for the new boards, so I have sime extra ceramics I can send you (10, 22, 100, 150 and 220pF).
That bridge looks fine.
Send me an email if you can't find anything. We are switching our kits over to Silver Micas for the pf caps for the new boards, so I have sime extra ceramics I can send you (10, 22, 100, 150 and 220pF).
Brian - why the switch to silvered mica's? C0G or NP0 are supposedly just as stable if that is the concern.
Well, it's really just a pin spacing issue. Russ changed the layout a bit, and used 5mm pin spacing. Silver micas are easy to find in that size (I guess ceramics are too), but I just decided. No other reason. C0Gs are great for the application.
Similarly, the rectifier bridge and the input cap supplied sound great to me, and they are what I use, but we will likely be offering optional upgrade to MUR860s and a 1uF Wima MKP10 for the input cap.
Similarly, the rectifier bridge and the input cap supplied sound great to me, and they are what I use, but we will likely be offering optional upgrade to MUR860s and a 1uF Wima MKP10 for the input cap.
Caps in pf values
I doubt if you can hear the difference. But a lot of people do not like using any type of ceramic caps.
One downside to the silver mica is that most of recent manufacture use steel leads. This is an even bigger issue with people who worry about parts selection than ceramic caps.
I have built mine with mainly silver mica caps that have copper leads. Life is too short to try to sort out the sonic impact of pf value caps.
George
BTW, how is the order of "new" circuit boards coming?
I doubt if you can hear the difference. But a lot of people do not like using any type of ceramic caps.
One downside to the silver mica is that most of recent manufacture use steel leads. This is an even bigger issue with people who worry about parts selection than ceramic caps.
I have built mine with mainly silver mica caps that have copper leads. Life is too short to try to sort out the sonic impact of pf value caps.
George
BTW, how is the order of "new" circuit boards coming?
Re: Caps in pf values
They are in and tested. Should be shipping very soon.
BTW I have use silver micas on nearly every MyRef I have built so far. Very happy with them.
Cheers!
Russ
Panelhead said:
They are in and tested. Should be shipping very soon.
BTW I have use silver micas on nearly every MyRef I have built so far. Very happy with them.
Cheers!
Russ
