Hi folks tubes aren't exactly my area of expertise so I'd be happy if someone could cast an eye over the listing for a cheap kit I found. It even has pics of the board and a circuit diagram which seems quite rare for an eBay listing. https://www.ebay.com/itm/154151985365
Cheers. D
Cheers. D
I would personally not buy/make it. It runs on only 60 V, so the voltage over the triode sections will be less than that because there will be some voltage drop over the 12K and 470 Ohm resistors in the cathode lead.
But opinions may/will differ from person to person. It is a cathode follower, so has inherently lots of negative feedback, maybe minimizing the possible effect of the low voltage over the triode sections.
But opinions may/will differ from person to person. It is a cathode follower, so has inherently lots of negative feedback, maybe minimizing the possible effect of the low voltage over the triode sections.
If you're interested, here's my take on a stereo tube buffer:
https://www.diyaudio.com/community/threads/photo-gallery.71300/page-529#post-6783689
https://www.diyaudio.com/community/threads/photo-gallery.71300/page-529#post-6783689
@Kwadjo thanks for your input, I had reservations myself. The hunt continues....
@kodabmx that looks like a nice buffer bud, I couldn't fit both boards in the same enclosure along with the tpa3126 board i have coming which is my main aim at present. I might have to revise this though if nothing compact and decent enough comes up. I'd really like a buffer board with those miniature valves fitted but I rarely see them in anything except a few commercial offerings.
Cheers. D
@kodabmx that looks like a nice buffer bud, I couldn't fit both boards in the same enclosure along with the tpa3126 board i have coming which is my main aim at present. I might have to revise this though if nothing compact and decent enough comes up. I'd really like a buffer board with those miniature valves fitted but I rarely see them in anything except a few commercial offerings.
Cheers. D
I thought you had a separate PSU board to power that buffer. Must have picked it up wrong lol another sign I'm getting old
No I do. I though you thought it was a mono buffer needing two of them. My mistake LOL
My entire preamp can actually run from a car battery. I can do it with a power amp, too. I'm not sure with they are really designed for, but those 12V inverters that make HV are nice. I have one that makes up to 1000 watts of 380V from 12V. I can only guess you can run a standard SMPS from 380VDC so you can make a cheap battery backup.
My entire preamp can actually run from a car battery. I can do it with a power amp, too. I'm not sure with they are really designed for, but those 12V inverters that make HV are nice. I have one that makes up to 1000 watts of 380V from 12V. I can only guess you can run a standard SMPS from 380VDC so you can make a cheap battery backup.
That's a great workaround using a cheap inverter. The main thing that always put me off building tube amps is the cost of decent transformers but if an inverter works well enough without adding any significant noise , well that's a bit of a game changer in my humble opinion. I used to be asked to install an inverter sometimes but that was in boats lol i bet lots of tube guys wouldn't consider using one to power an HT circuit but experimenting is the best part of this hobby/obsession 😁
I used to have a mini chipamp in a box with a pair of 12V slabs, it was actually quite decent but it only got occasional use so the batteries met an early end from being left discharged. Lead acid batteries were a bad choice, outdoor parties are few in the West of Scotland 😬
I used to have a mini chipamp in a box with a pair of 12V slabs, it was actually quite decent but it only got occasional use so the batteries met an early end from being left discharged. Lead acid batteries were a bad choice, outdoor parties are few in the West of Scotland 😬