"but my mother passed away this morning (expected, she was 90 and in poor health) "
Very sorry to hear that. My condolences. The tube stuff can wait. We'll be waiting to hear from you. We just had a very bad medical diagnosis in the family here recently too. Just when you think life is starting to cruise along ...... Some trips coming up.
Very sorry to hear that. My condolences. The tube stuff can wait. We'll be waiting to hear from you. We just had a very bad medical diagnosis in the family here recently too. Just when you think life is starting to cruise along ...... Some trips coming up.
Just got the computer fired up, sitting in a hotel room in Langfang China. It's noon here or 11pm depending where your head still is... Thought I'd see if I could log in.
My heart is also heavy with your loss, my mother also passed this summer at 99. Even though it is expected, one is never ready to let them go. I was sitting in her hospital room at the wee hrs of the AM when I stumbled onto a tube site, and I decided to read it as we watched over her. Dad was into tubes but passed when I was young. Tubes, amps, to me are a touch of their legacy that I decided to hang onto and pass it along to our son (Compactron Amp stocking stuffer at Christmas) and to his son when he can start to understand (currently 3.5). So as I sit sketching designs and doing PCB layouts, it is due to my parents and I shall remember it always.
I'm looking forward to being home in a few weeks, still have an amp to complete....
My heart is also heavy with your loss, my mother also passed this summer at 99. Even though it is expected, one is never ready to let them go. I was sitting in her hospital room at the wee hrs of the AM when I stumbled onto a tube site, and I decided to read it as we watched over her. Dad was into tubes but passed when I was young. Tubes, amps, to me are a touch of their legacy that I decided to hang onto and pass it along to our son (Compactron Amp stocking stuffer at Christmas) and to his son when he can start to understand (currently 3.5). So as I sit sketching designs and doing PCB layouts, it is due to my parents and I shall remember it always.
I'm looking forward to being home in a few weeks, still have an amp to complete....
If lots of people are going to build a souped-up red board, it may pay to come up with a custom Edcor. It would be a big one, but something with 460-0-460 secondary for the sweep tube plates that has a pair of 280-0-280 taps for the PCB (now "C+") and 70-0-70 taps for the bias/CCS "C-" rail would be perfect.
Obviously, a pair of 10 pounders would be cheaper, but that is not a reliable resource. Another alternative is a pair of Anteks. Say AN-4T450 for the sweep tubes and a AN-4TK360 for the PCB. Lots of excess 6.3V windings!
Obviously, a pair of 10 pounders would be cheaper, but that is not a reliable resource. Another alternative is a pair of Anteks. Say AN-4T450 for the sweep tubes and a AN-4TK360 for the PCB. Lots of excess 6.3V windings!
I've read the term several times: "ten pounder". But I missed the source/description.
Stuart
An eBay seller was selling some cosmetically-challenged power transformers for cheap.:
http://www.diyaudio.com/forums/tubes-valves/169867-10-pounds-power-15-a.html
They are gone now.
Thanks anyway. I just ordered a pair of Antek AS-4T400. Should do the trick and not too pricey. Sadly, toroids.
Stuart
If someone will post all of the specs needed I will make the order and pay the extra $ to make it a standard item. Did not get in on the ten pounders. I would also like suggestions on output tubes with a plate cap. I would also like to order opts qt the Sam time. Is 3k3 100watt what I want? What drivers ?
I like the idea of filtering power line noise with a limited bandwidth EI core transformer.
Stuart
Well, let's see. The stock transformer is rated at 200mA. Pete's suggests 40mA per tube for bias at 340V B+ and George is running 35mA@600V. So it seems like 200mA should be enough, but maybe 250mA to be safe. The 6.3V winding needs to be hefty. 2.5A per tube for 6LR6, so 10A just for those.
The stock transformer is sized for a 18 WPC amp.
35 to 40 mA is the idle current. The current for a 125 WPC amp at full crank is just over 1/2 Amp. Obviously the amp is not going to sit at full power all the time, unless you are running an industrial shaker table or something. Depending on the efficiency of the speakers, the type of music being played, and how deaf you are (or going to be), the average power will be in the 10 to 25 WPC range. This adds about 80 to 120 mA to the idle numbers and the drivers eat about 30 mA. The amp will idle at about 190 mA. Current peaks will go over 500mA. I would go for a 250 to 300 mA transformer. More if you like disco......
I am beginning to think that the cheapest route will be a moderate sized conventional EI transformer for powering the board and a big ugly Antek under the deck just for the plate supply.
My amp is stashed in the closet right now. The Mouser box arrived so I will be stuffing parts into TWO brand new red boards. One of them will be built just like the one on the breadboard. It will be powered by two 10 pounders and run 6HJ5's. The other......... Any ideas?
To get around 600volts out of one of the anteks wouldn't one need to purchase one with secondaries around 430volts or so? I had given some thought to using one ten pounder to run the whole board and an antek for the plates but since I have these black anvils already I might as well use them.
I need some speakers now that can take the abuse this amp is able to unleash.
I need some speakers now that can take the abuse this amp is able to unleash.