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.
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...
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
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).
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?
