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Re: DIY thoughts of the day
Posted: Wed Dec 11, 2019 12:36 pm
by TheMadMick
Ali
Much obliged. I'm afraid my ability to read valve datasheets is very limited so no straight answer fro me then? I've contacted Duncan Amps to get some advice.
Will the 5751 use the same parameters as the 6 SL7 noting the 5751 is a pentode and the 76SL7 a triode?
Cheers.
Re: DIY thoughts of the day
Posted: Wed Dec 11, 2019 12:51 pm
by Ali Tait
Nick will know more than me, but I do know many people using WAD phono stages swapped ECC83's to 5751 to lower gain, and it would appear the 6sl7 can usually be subbed with ECC83-
https://www.diyaudio.com/forums/tubes-v ... 12ax7.html
Re: DIY thoughts of the day
Posted: Sun Feb 16, 2020 4:04 pm
by karatestu
I found a couple of old but little used Kendeil 22,000 uf caps which i forgot that i had
I will probably need to reform them and as i don't have an esr meter i won't be able to measure them
I used them in a Naim hicap many moons ago. Size of bloody coke cans
What should i use them for i wonder ?
Re: DIY thoughts of the day
Posted: Sun Feb 16, 2020 4:12 pm
by karatestu
I will have some spare 3.3 uf K75-10 Russian paper in oil caps as well when my 1 uf ones arrive.
I was advised a while ago that they were only good for crossovers but i have a very inquisitive mind so will have to find out for myself. But as DQ commented the other day, the fewer of them used the better.
Re: DIY thoughts of the day
Posted: Mon Feb 17, 2020 4:59 pm
by karatestu
Why do people obsess about frequencies above 14KHz. Us over 40's can't even bloody hear that high. Only children should be concerned
Re: DIY thoughts of the day
Posted: Mon Feb 17, 2020 5:30 pm
by Ali Tait
Not very scientific admittedly, but various smartphone apps show I can still hear around 17k, not bad for 51.
Re: DIY thoughts of the day
Posted: Mon Feb 17, 2020 5:35 pm
by karatestu
Ali Tait wrote: ↑Mon Feb 17, 2020 5:30 pm
Not very scientific admittedly, but various smartphone apps show I can still hear around 17k, not bad for 51.
You have obviously looked after your ears. Myself on the other hand...........oh dear
Re: DIY thoughts of the day
Posted: Mon Feb 17, 2020 7:32 pm
by Ali Tait
Was always careful with ear defenders in the past. 30 years ago, a neighbour bought an “ultrasonic” anti vermin device to get rid of the mice in his shed. I could hear the bloody thing, and he had it on 24/7. Thankfully he got rid of it when asked, it kept me awake lol.
Re: DIY thoughts of the day
Posted: Mon Feb 17, 2020 10:31 pm
by TheMadMick
karatestu wrote: ↑Mon Feb 17, 2020 4:59 pm
Why do people obsess about frequencies above 14KHz. Us over 40's can't even bloody hear that high. Only children should be concerned
Not sure things are as simple as that. From what I can glean, the basis of MQA is that we can "sense" frequencies over 20kHz. How exactly that works I'm not sure. Some argue that is why vinyl sounds better than CD (although there is probably another debate there) because very high frequencies get out and we like that.
Ho Hum. There are more things in heaven and earth than are dreamt of in your philosophy Horatio?
Re: DIY thoughts of the day
Posted: Mon Feb 17, 2020 11:52 pm
by CN211276
TheMadMick wrote: ↑Mon Feb 17, 2020 10:31 pm
karatestu wrote: ↑Mon Feb 17, 2020 4:59 pm
Why do people obsess about frequencies above 14KHz. Us over 40's can't even bloody hear that high. Only children should be concerned
Not sure things are as simple as that. From what I can glean, the basis of MQA is that we can "sense" frequencies over 20kHz. How exactly that works I'm not sure. Some argue that is why vinyl sounds better than CD (although there is probably another debate there) because very high frequencies get out and we like that.
Ho Hum. There are more things in heaven and earth than are dreamt of in your philosophy Horatio?
I believe that the reproduction of frequencies well beyond the range of human hearing effect our enjoyment of music and think that the extent to which it occurs varies from individual to individual. I think this goes some way to explaining why many prefer vinyl to CD. The 44 kHv cap is too low.