ramtubes
thanks for the info on tube amps/ speakers!!
thanks for the info on tube amps/ speakers!!
Does anyone care to ask an amplifier designer a technical question? My door is open.
@atmasphere, "I don't use the word 'believe' because I made the measurements which showed that the power cord **without question** can affect the amplifier's performance. The measurement is easy- the voltage drop from one end of the power cord to the other. Its not rocket science and its not mumbo jumbo woo. Anyone with a 3 1/2 digit DVM can do it. After you know what the voltage drop across the cord is, then measure the resulting differences in the amplifier: output power, distortion and output impedance. You will find that they all change. So by this simple means you have a tool to correlate with what you hear. So in a nutshell, I don't believe it, I **know** it." Ralph, thanks for providing this insight. I have been accustomed to thinking about power supply to amplifiers primarily as avoiding reduced current supply, not avoiding voltage drop. I had not really considered voltage drop before. I was especially intrigued by your statement regarding measurability of differenced in distortion as a consequence of voltage drop. My power usually measures around 120-123V from the duplex, in other words, it is a bit on the high side. I run my system through a PS Audio P-10 with the voltage set at 117 V (tube life!) , but my M-60s are supplied straight from the wall. They are not happy running through the P-10! From the point of view of distortion from the M-60's as a function of voltage, would you expect a measurable difference in distortion over the range of 115-125 Volts? |
* Discussion on diode transients and measurement thereof here: https://electronics.stackexchange.com/questions/323507/bridge-rectifier-4-diodes-vs-single-chip Not much meat or it sounds. I didnt read the whole thimg. In my RM-5 preamp I found the coupling of the power transformer to make a great difference. A well coupled primary has less noise, however a loosely coupled primary was worse. Takes some digging to see this. I felt it best to use the Grid to take the pulses. What a cord might do I, dont think much. I would like to see some scope photos of these diodes compared to others all the way down to the slow 1N4000 series. |
my M-60s are supplied straight from the wall. They are not happy running through the P-10! From the point of view of distortion from the M-60's as a function of voltage, would you expect a measurable difference in distortion over the range of 115-125 Volts?You would certainly be able to measure a difference, not just distortion but also power. It seems that conditioners like the P10 are not happy with higher constant loads on them- they work fine with higher power solid state amps that have otherwise low quiescent current draw, but tube amps with larger draws (for filament circuits, perhaps also class A) seem to cause them trouble. For that reason we usually recommend running the amps straight out of the wall. If you want a really nice conditioner, a company called Elgar used to make some that are quite impressive. |