Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Ed_Chambley on February 21, 2018, 11:58:30 am
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I actually found a AO-63 I had stashed away. This schematic is correct I have attached. Sluckey did a converion if this, so I know it works. My question is this amp has inductor input, but has 2 in series. Looking at them, the seem very small and I cannot seem to find the specs on them.
The 2 are L300 and L301 and my amp is this older version. The newer versions have 1 inductor and is way bigger than the 2 combined in series on my amp.
My question, are series inductors capable of handling more amperage?
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handling more amperage?
pretty sure inductors are the same as R's, so series no, in || yes. I believe more henrys "resist" current change more.
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My question, are series inductors capable of handling more amperage?
No, but the total inductance will be the sum of the two chokes, just like putting two resistors in series. Some of the big 4 tube Sunns used two chokes in parallel to double the current handling capacity.
I have the same AO-63 with two small chokes. They are plenty big for that amp. As you already noticed, this is a true choke input power supply filter. You need to stick to the choke input . Otherwise your B+ will be extremely high if you try to put a cap in front of the chokes. That PT puts out 430-0-430 VAC!
Also notice the HT secondary winding has lower voltage taps that feed another rectifier to produce a much lower voltage for the 6GW8 power amp (reverb).
Wha'cha gonna do with it?
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My question, are series inductors capable of handling more amperage?
No, but the total inductance will be the sum of the two chokes, just like putting two resistors in series. Some of the big 4 tube Sunns used two chokes in parallel to double the current handling capacity.
I have the same AO-63 with two small chokes. They are plenty big for that amp. As you already noticed, this is a true choke input power supply filter. You need to stick to the choke input . Otherwise your B+ will be extremely high if you try to put a cap in front of the chokes. That PT puts out 430-0-430 VAC!
Also notice the HT secondary winding has lower voltage taps that feed another rectifier to produce a much lower voltage for the 6GW8 power amp (reverb).
Wha'cha gonna do with it?
Well, I plan to build a Bogner Extacy since it has AMPEG Tubes. Don't you love my smart replies?
I built the a Gemeni preamp on the Breadboard and tied it to a Cap input power section with 2 6L6's and it sounded ok. I pulled out an a 2 henry, 200 ma Choke I had around.
Guess What? Oh glory be, it is not the Sunn cab. It is the damn choke input.
OK the cat is out of the bag. Yes, I have played Sluckeys Hampeg and it has the best clean tone I have ever heard. I had planned to build an Ampeg. The Stones used Ampegs on the early 70's when Keef was influences by Graham Parsons and I could hear Tumblin Dice even though I was not G tuned and capo at 4.
That is twangin goodness, great verb and tremolo and just loves an old Broadcaster Bridge PUP.
I have read inductors in series simply increase inductance like resistors when in series. The chokes look small compared to what I usually look for. Usually, I prefer the AO-15 that you find in the JR-20 tone cabinet. Here I can make the 20 watt, 40 watt amp. 20 watts mono, 40 watts stereo.
It is more work than converting an AO-43, but the result is much more flexibility. It is sort of difficult to reuse the chassis as it is long, very long.
I am wanting to Replace my 62 Bassman that I use in my larger rig along with my modded JTM 45. I have found all the original components and restored the bassman to its original glory and everytime I take it somewhere it gets wear. Doesn't make sense to keep gigging it and destroy the appearance.
So I need a new 50ish watt clean, snappin, poppin, twanging, rockin, reverberating, tremolo shaking, Modulation making lovin machine.
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can you even get 50W out of a pair of 7591? ...or is 45W with 50W in clipping "close enough?"
--pete
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The book values go to 45W.
Which is a lot for a pair of old-rating 6L6.
I don't know why 40W is disappointing.
I do bet I could get 80 Watts... for a few seconds.
_MY_ preference would be to lose the "high gain" aspect of 7591 and go for reliable old 6L6(GC).
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The book values go to 45W.
Which is a lot for a pair of old-rating 6L6.
I don't know why 40W is disappointing.
I do bet I could get 80 Watts... for a few seconds.
_MY_ preference would be to lose the "high gain" aspect of 7591 and go for reliable old 6L6(GC).
I checked a Pair of 6L6GC and they sounded the same when producing clean tone. Of coures, I have a few 7591's so I will use the up.
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Be careful! The bias supply in the AO-63 only puts out -22vdc.