donsachs
Responses from donsachs
| 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... | |
| 300b lovers The preamp and amps use regulated DC filament supplies in all positions. | |
| 300b lovers Lastly, I have said this before in this thread. It is about your design goals. We could make a low powered amp that uses 45 tubes in push pull and it would produce maybe 5-10 watts and stay in class A. I am sure it would sound incredible. If y... | |
| 300b lovers What @pindac described is exactly what I heard when I first built the rather primitive initial "silicon assisted" stereo version of this circuit with a CCS on the plate of the driver tubes and a single regulated supply for each channel. I could h... | |
| 300b lovers NFB covers a lot of sins. You have to do everything right to have a stable circuit without it. It is actually considerably more complicated than that, but that is a good way to think about it. That allnic amp ad boasts a perfect square wave re... | |
| 300b lovers @spazzghettie Looks like a nice amp. LC coupled and they use all DHT tubes. On the downside it is single ended so it won't have the bass punch nor the power of a push pull 300b. Also, I have moved on from LC coupling as I prefer custom inters... | |
| 300b lovers I have only had 3 or 4 pairs of the tennis ball psvane 6sn7 tubes come through here and I have yet to see a microphonic pair. I still prefer the sound of the Linlai E-6SN7 though. @1markr I think you will love the Linlai WE300b. They take may... | |
| 300b lovers @1markr I have not heard the original WE300b, but I have heard many of the $400-500 per quad 300b tubes and then I heard the Gold Lion 300b, which was a definite step up. Then I got the Linlai WE300b copy and it is a far better tube than the Go... |