donsachs
Responses from donsachs
| 300b lovers I have explored all sorts of variants of this basic circuit for about two years now, and have learned what I like and understood why. This is a deceptively simple circuit, except that there is subtle complexity. Often, we get caught up in the ... | |
| 300b lovers No, the comparison isn't really fair. The little Chinese amp is a nice value for the money, but it is a single ended design made of, shall we say, "cost effective" parts. It probably makes 7 or 8 watts per channel. The mono 300b amps are built... | |
| 300b lovers The regulated filament supplies for each 300b can deliver 3 amps, and the tubes draw 1.2 amps, so they are coasting along, like the B+ supplies. As Lynn described, the amp is lightning fast. I would love to audition the Elrog 300b in it. I ha... | |
| 300b lovers Charles, I am not sure what Meyer would think of the Blackbird! There are some elements of it that are aligned with his thinking and others that are radically different. I would be interested to hear some amp of similar power that he has built ... | |
| 300b lovers Thomas Mayer builds seriously good amplifiers:) I have his octal phono circuit saved, and one day I will build myself another phono preamp with my power supply and his signal circuit. I bet it will sound very good. His tube blog is wonderful. | |
| 300b lovers @alexberger Spatial Audio Lab will be in charge of presentation at shows. I know we are returning to the Pacific Audio Fest in Seattle again next summer. Beyond that I don't know. We are focusing on getting the preamp and amps into production... | |
| 300b lovers I managed to update my ancient website with the beginnings of 300b project page. There is a photo of the final prototype of the Blackbird 300b monoblock amp at the bottom of this page. Spatial will change the look a bit, but dimensions and layou... | |
| 300b lovers Yes, we are pretty much back to an updated Karna circuit with more modern power supply topology, and custom wound iron everywhere. I listened to every possible variant of the circuit and it is obvious that removing all coupling caps and going wit... | |
| 300b lovers @atmasphere First off, this thread was started by a fellow who has a rough first prototype of a zero feedback push pull 300b amp, so of course we are discussing that. I agree that in that circuit you hear everything. I will tell you that even ... | |
| 300b lovers As I said above, there are little tricks to regulated DC filament supplies on DHTs.... | |
| 300b lovers We all apply sound engineering practice. We overbuild all power supplies and over spec all parts. But there are choices that affect the sound. If you need a 1 watt 1K resistor you can use any type on a cathode, but different types have differen... | |
| 300b lovers There are a lot of little tricks to DC filament supplies that make them sound better too. It isn't rocket science, but you can get a bit more performance and noise rejection by connecting them properly:) | |
| 300b lovers @alexberger Hi. I just tried schottky diodes maybe 5 or 6 years ago and I liked the sound. They have a fast recovery time. They also have very low voltage drop so are good for small filament supplies, but the main reason is the fast recovery.... | |
| 300b lovers Regulated high voltage supplies are also a very hot button issue. I know what I prefer from having built the same circuit with multiple power supply topologies and critically listened to each. The way I do it costs more money and certainly has ... | |
| 300b lovers @charles1dad Well, let's just say I have experimented and know which I prefer:) The 300b amps have a dedicated 5V regulated DC supply for each 300b tube and a 6.3V DC regulated supply for the drivers and input tube. The preamp has a 6.3 V regu... |