Well it's been a long day, learned lot's.
So far it's looking easiest to build the RH84 with the 12AT7 front end and 6V6 output.
I'll start on it tomorrow (breadboard). I'm not set in stone on the 12AT7, I still have a few other tubes to look at, or if someone has any suggestions from my list above. Thanks
AL
So far it's looking easiest to build the RH84 with the 12AT7 front end and 6V6 output.
I'll start on it tomorrow (breadboard). I'm not set in stone on the 12AT7, I still have a few other tubes to look at, or if someone has any suggestions from my list above. Thanks
AL
Well I kind of hit a wall with the PSUD program, can't for the life of me figure out how to input a pi filter in there. Still might be useful for some other project down the road.
I'm playing with the power supplies now.
Quick question with regard to the Choke on the RH84,
I have a 1HY - 51 Ohm choke, though not ideal, can I use it?
(RH84 Schematic calls for 20HY)
I'm playing with the power supplies now.
Quick question with regard to the Choke on the RH84,
I have a 1HY - 51 Ohm choke, though not ideal, can I use it?
(RH84 Schematic calls for 20HY)
Ok making some progress with the PSUD and breadboard.
What's a ball park figure for the load of the RH84?
Right now I'm just using 100ma (R=V/I) , so for 319v I get a 3K load resistor.
I'm shooting for 300v B+ as per RH84 schematic. I know I should figure it out my self, and I am trying, I swear. lol.
What's a ball park figure for the load of the RH84?
Right now I'm just using 100ma (R=V/I) , so for 319v I get a 3K load resistor.
I'm shooting for 300v B+ as per RH84 schematic. I know I should figure it out my self, and I am trying, I swear. lol.
Looks great Bruce! Nice new iron too. Thanks for the upload and info.
Here's what mine looks like so far. Just in the breadboard stage.
It was a good suggestion that the other fellow made to make it non permanent. I salvaged some sockets etc. from old amps. It's nice because I will have the parts leftover to mock up other projects down the road.
I did have to rotate the socket for the rectifier so that pins 2 and 4 are vertical on the 5Y3. The 5UG wants pins 1 and 4 vertical, so I just split the difference.
So are you using your for your primary amp for day to day use?
Just curious what size choke you got away with? (I only have a extra 1HY at the moment, although I think it should work for now.) I might have read what you used but just don't recall at the moment.
That's my plan if the bass response is decent. My other amp that I built has eleven tubes burning away, seems a little wasteful at times just for watching TV.
Don't get me wrong,I absolutely love the 6CG7/6V6PPP and would never part with it unless I was building another amp of the same caliber.
Really looking forward to hearing RH84. I'll keep you updated, I'm sure I'll have more questions.
AL
Here's what mine looks like so far. Just in the breadboard stage.
It was a good suggestion that the other fellow made to make it non permanent. I salvaged some sockets etc. from old amps. It's nice because I will have the parts leftover to mock up other projects down the road.
I did have to rotate the socket for the rectifier so that pins 2 and 4 are vertical on the 5Y3. The 5UG wants pins 1 and 4 vertical, so I just split the difference.
So are you using your for your primary amp for day to day use?
Just curious what size choke you got away with? (I only have a extra 1HY at the moment, although I think it should work for now.) I might have read what you used but just don't recall at the moment.
That's my plan if the bass response is decent. My other amp that I built has eleven tubes burning away, seems a little wasteful at times just for watching TV.
Don't get me wrong,I absolutely love the 6CG7/6V6PPP and would never part with it unless I was building another amp of the same caliber.
Really looking forward to hearing RH84. I'll keep you updated, I'm sure I'll have more questions.
AL
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Hey as long as it works.
I use those clips for mocking up lots of SS stuff, although my clips seemed a little weak, sometimes one would let go if you moved the board and leave you wondering whats wrong, lol. The clear plastic is a good idea.
Well your choke seems to be bigger then the one I have. I might have another one somewhere. I got a monster of a choke from an old HP-23 HAM radio power supply in use in my other amp. I should have a look around and see if I have another hiding.
So would you say the RH84 is your favorite? Not really a fair comparison topology wise, but they are similar in size.
I use those clips for mocking up lots of SS stuff, although my clips seemed a little weak, sometimes one would let go if you moved the board and leave you wondering whats wrong, lol. The clear plastic is a good idea.
Well your choke seems to be bigger then the one I have. I might have another one somewhere. I got a monster of a choke from an old HP-23 HAM radio power supply in use in my other amp. I should have a look around and see if I have another hiding.
So would you say the RH84 is your favorite? Not really a fair comparison topology wise, but they are similar in size.
OK, so I have 305V with tubes in (should be 300v), close enough.
I've got 47uf and 150uf caps in the pi filter. Schematic calls for 220uf for the second cap.
Now it is my understanding that the first cap should be lower and the second cap can be what ever value you like. I did find with the PSUD that I was getting forward current warnings with just about every combo I tried, goes against what I've been told, the second cap does seem to reflect a change in rectifier current. According to the program anyways.
I've got 47uf and 150uf caps in the pi filter. Schematic calls for 220uf for the second cap.
Now it is my understanding that the first cap should be lower and the second cap can be what ever value you like. I did find with the PSUD that I was getting forward current warnings with just about every combo I tried, goes against what I've been told, the second cap does seem to reflect a change in rectifier current. According to the program anyways.
I have six speakers per channel wired up to give me ~8ohms.
Sounds pretty decent I suppose. I'm not exactly blown away but it does seem to have slightly better imaging then my 6CG7/6V6 PPP amp at low volume. That's about it. I guess this says a lot about my PPP. Might try some different tubes in it. I tried to have neutral expectations, but I was expecting some goosebumps. It's not any worse then my PPP, thank goodness.
The bass is satisfactory, so all in all it's a good candidate for a lower powered daily driver.
I will build this amp in to a nice enclosure unless somebody has any other suggestions to try.
AL
Sounds pretty decent I suppose. I'm not exactly blown away but it does seem to have slightly better imaging then my 6CG7/6V6 PPP amp at low volume. That's about it. I guess this says a lot about my PPP. Might try some different tubes in it. I tried to have neutral expectations, but I was expecting some goosebumps. It's not any worse then my PPP, thank goodness.
The bass is satisfactory, so all in all it's a good candidate for a lower powered daily driver.
I will build this amp in to a nice enclosure unless somebody has any other suggestions to try.
AL
I still like the RH84, I think this calls for a look into a third amp.
I just tried some different 6V6s in it, also sounds great, so I suppose the first set of 6V6 were weak. (Tube tester needs TLC), thats's why I noticed such a difference. Should have done that before posting, sorry.
I just tried some different 6V6s in it, also sounds great, so I suppose the first set of 6V6 were weak. (Tube tester needs TLC), thats's why I noticed such a difference. Should have done that before posting, sorry.
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