I had a similar situation where the wire separated from the female receiver inside the input molex . The fault (loose crimp) was there just about to break, but touching/moving the amp made it show up. I removed the pins and soldered directly to the board from the input RCAs to avoid that. Hope it's something that simple. 
Attachments
Last edited:
Hi Bcmbob,
I have resoldered all solder joints of input section. Same issue. When inputs are shorted, there is no noise. But it is difficult to listen to music if inputs of amplifier are shorted 😉
As noise already increases when I put my finger a few mm apart from input capacitor, this indicate some kind of open loop gain and behavior like of a touchless sensor.
I guess the LM318 is not working properly. Have no spare LM318 on hand to test.
1534
I have resoldered all solder joints of input section. Same issue. When inputs are shorted, there is no noise. But it is difficult to listen to music if inputs of amplifier are shorted 😉
As noise already increases when I put my finger a few mm apart from input capacitor, this indicate some kind of open loop gain and behavior like of a touchless sensor.
I guess the LM318 is not working properly. Have no spare LM318 on hand to test.
1534
Are you using the Russian metal can caps at the input? Some hum problems were reported if they were not mounted properly.
No, I am using Audyn Tin Foil Caps. Other channel having same type of cap is working properly. The noise \ hum is not that noise what you can hear in near range only, it is on a level that you can hear at a 15m distance.
I try to get a spare LM318. I guess there was a instability caused by crossover failure which has destroyed something in LM318 chip.
I try to get a spare LM318. I guess there was a instability caused by crossover failure which has destroyed something in LM318 chip.
Sorry to hear that...
I think the opamps (starting from the LM318) are a good bet, I don't think passives could get damaged by the injected digital signal.
The hum you hear putting your finger near the input cap is normal.
I think the opamps (starting from the LM318) are a good bet, I don't think passives could get damaged by the injected digital signal.
The hum you hear putting your finger near the input cap is normal.
Last edited:
Hello Fremen,
any comments on the Amtrans AMRG Resistor vs the Riken ? I'm looking to get parts from Hfc as im in the uk. Also looking at cerafines or silmics for C9.
Just bying the Rikens from America seems inefficient - tho im contemplating the k71-4 C13 - at 8x for 26 euros from Sovtube in the ukraine.
What worries me is that little has been mentioned of these things - am i ploughing though the wrong threads????
any comments on the Amtrans AMRG Resistor vs the Riken ? I'm looking to get parts from Hfc as im in the uk. Also looking at cerafines or silmics for C9.
Just bying the Rikens from America seems inefficient - tho im contemplating the k71-4 C13 - at 8x for 26 euros from Sovtube in the ukraine.
What worries me is that little has been mentioned of these things - am i ploughing though the wrong threads????
suposed to read -> Hello Fremen builders.... (no idea where the edit button is)
classically there is only 1 AMRG in the right value at Hfc anyway ....
BG-PK 220uF/4V was a pretty good choice for C9, but the last remaining volume source (Parts Connexion) has raised prices by a factor of 4-5x recently. That leaves Cerafines, Silmic IIs, Nichicon Muse KZ (my favourite at C9) and a few others which haven't been evaluated in detail: Rubycon YXA, YXG, ZLG and some generic Elnas including RJJ, RJH, RSE, RSH, RE3, RJ4, etc.
I had tried a radial-lead 1uF K71 earlier in one of my builds, but I replaced it with a 1.8uF K73-16 axial PETP today, and I'm much happier. It doesn't have the same analytical micro-detail of the K71, but it is more cohesive and musical. I'll audition it for a while to get a more complete picture, but it looks like it will stay for now.
Finally on, I'm testing now ... fantastic.🙂
Only now I find all the limitations of my old speakers, the offset vacuum is 3.8 mV and 5.2 mV, everything ok on the first turn ... I can just place some photo assembly and houses made with materials taken from the "garbage" of the lab where I work. 😀
For power I used 4 EI transformer insulation 0-24V 144VA, these recycled material, I still do not regret the torus. 😀
When I have time I make serious measures.
Enjoy everyone.
(...and sorry for my bad English)
Only now I find all the limitations of my old speakers, the offset vacuum is 3.8 mV and 5.2 mV, everything ok on the first turn ... I can just place some photo assembly and houses made with materials taken from the "garbage" of the lab where I work. 😀
For power I used 4 EI transformer insulation 0-24V 144VA, these recycled material, I still do not regret the torus. 😀
When I have time I make serious measures.
Enjoy everyone.
(...and sorry for my bad English)
I'm sorry to hear about the BG PK getting pricey. Parts Connexion originally had quite a few. They must finally be coming to the end.
Just curious, which radial lead K71 did you try? I've seen K71-7 radial caps in smaller sizes, but nothing approaching 1 uF.
More C13 playing around
I have recently been upgrading my speaker crossover components and that is leading me to go back and consider C13. I plan on going through a number of parts that I already have and some new ones.
One of the new ones I recently tried are the last of the old stock of Ampohm Paper in wax and tin foil caps at "the tube store" in Canada. When I say the last, I literally got the last two in stock. I have to say that they are surprisingly good with lots of detail, clarity, and full bass (at least once they get broken in). If someone is looking to try something unique, "the tube store" has a few of the paper in wax and aluminum foil, plus a few of the more expensive paper in oil and copper foil left in 1 uF. Also, HiFiCollective has some Ampohms left, but they are becoming scarce everywhere. Too bad they didn't make it.
I am looking forward to comparing the Ampohms to some Mundorf's (per Dario's suggestion), and other caps on my shelf, once I get the last tweaks into the crossover.
I have recently been upgrading my speaker crossover components and that is leading me to go back and consider C13. I plan on going through a number of parts that I already have and some new ones.
One of the new ones I recently tried are the last of the old stock of Ampohm Paper in wax and tin foil caps at "the tube store" in Canada. When I say the last, I literally got the last two in stock. I have to say that they are surprisingly good with lots of detail, clarity, and full bass (at least once they get broken in). If someone is looking to try something unique, "the tube store" has a few of the paper in wax and aluminum foil, plus a few of the more expensive paper in oil and copper foil left in 1 uF. Also, HiFiCollective has some Ampohms left, but they are becoming scarce everywhere. Too bad they didn't make it.
I am looking forward to comparing the Ampohms to some Mundorf's (per Dario's suggestion), and other caps on my shelf, once I get the last tweaks into the crossover.
Sorry didn't compared Amtrans Vs Rikens on the MyRef.
But I did on the DCB1, they sound very similar, Amtrans a bit more neutral.
BTW you're on the right thread 😉
Regarding C9 you can use 'Gold' Silmic II you can find on ebay, really fine sounding, they hide a bit of detail, though... you can fix it bypassing with 22nF FKP2
Regarding RJHs I've tried them also on C9, not bad but nothing to bother about, IMHO.
🙂
Waiting for pics 😉
For the bottom, the central bulkhead, and the above, I used 3mm anodized aluminum recovered from a rack of automation disposed of, the heat sinks are the recovery of two industrial power supplies broken and I was bound for the size of the amp.
The boxed aluminum is 30x30mm and 172mm deep, and is the coating of the legs of my desk 🙄😀 ... ahahahahha
The front and the back is made of aluminum 4.5 mm 330x190 mm, this also coming from a closet automation disposed of, as well as the transformers that are the recovery of some safety sockets 24v.
For now it is a chassis provisional, but already I know that it will remain so for long.
is on for at least 6 hours on the speaker 12 ohms and it is just warm, no noise due to the processors that was my biggest fear.
As soon as I get a little sparrow of time to do some serious measuring.
Good life to all.
The boxed aluminum is 30x30mm and 172mm deep, and is the coating of the legs of my desk 🙄😀 ... ahahahahha
The front and the back is made of aluminum 4.5 mm 330x190 mm, this also coming from a closet automation disposed of, as well as the transformers that are the recovery of some safety sockets 24v.
For now it is a chassis provisional, but already I know that it will remain so for long.
is on for at least 6 hours on the speaker 12 ohms and it is just warm, no noise due to the processors that was my biggest fear.
As soon as I get a little sparrow of time to do some serious measuring.
Good life to all.
Attachments
K71-5, which is cylindrical with 3 leads (1 dummy) at the bottom, like a big electrolytic. The 1uF seems to be unobtainium now, but 0.47uF and smaller values still seem to be available.