Whenever I build an amp, years later I will remember the compromises I made more than the extra cost incurred by upgrades implemented. Monoblocks sound like a fun build, and you've got me thinking about my own Kegger KT-88 project list.
I'm with you on that, my RH-84 turned out great but I also want to build a new one with better outputs and better caps so I'm thinking if I build these as monoblocks with enough current ability I can always run even kt-120's and 150's pretty well with a bias adjustment.
 
BTW, this schematic is almost an exact copy of the "RH Universal" amp that was developed about 5 years ago. The only difference is the front end tube and the LED used on the cathode. You should check it out if you want to have more background on its development.
I'm going to be building a 2a3 amp while waiting for my edcor iron for this build but I'm thinking of building another RH amp next year so may go that route then or do the parallel rh84.
 
so it looks like my output stage would have about 50mv of ripple if I use a clc filter, how do I figure out how much will be going to my speakers? I will be using 100 db speakers.
 
So I ended up messing with the power supply design and got it down to around 1.5 mv. I'm just wondering around how much current the driver will draw for each channel?
 
Well, the umbilical is somewhat of an extra effort, but once you get the hardware sorted it is really not that hard to implement. You have 1 wire for the B+ , 1 wire for the ground, 2 wires for the heaters, That is about it. I have done a couple of amps this way. For a high power SE amp, the weight of the transformers, especially in a LCLC configuration, can be substantial so that is why i did it.
 
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Well, the umbilical is somewhat of an extra effort, but once you get the hardware sorted it is really not that hard to implement. You have 1 wire for the B+ , 1 wire for the ground, 2 wires for the heaters, That is about it. I have done a couple of amps this way. For a high power SE amp, the weight of the transformers, especially in a LCLC configuration, can be substantial so that is why i did it.
I hear you, I will think about it a bit. I've always have wanted to build mirrored mono blocks though and want to see if I notice better stereo separation. I do have some octal plugs for something planned down the line in a couple of years that I nicknamed "King Song" as a joke one late night, cant wait to start building that madness. Anyways I'm thinking my power supply above should work pretty well so I'll be doing a clclc filter. I thought I read somewhere that you've built the Kegger Kt-88 before, how did the sound compare to the rh-84? Was it sweeter?
 
Divide that by the turns ratio of the OPT and reduce that by the efficiency rating.
Thank you, I ended up looking it up in another thread. I'm going to be under 2mv of ripple on b+ so I'm set. This amp/speaker pair should end up putting out around 110db of clean audio 1 meter away which is plenty loud. For private listening I don't usually go above 95 db.
 
I thought I read somewhere that you've built the Kegger Kt-88 before, how did the sound compare to the rh-84? Was it sweeter?
Well, i actually made a SE 6l6 amp that was based on Keggar's schematic. Compared to the Alex Kitic design they both share the same qualities of very natural, dynamic, and realistic sound.
If you want to extract the most power from your amp you should install fixed bias. This has the advantage of deleting the large cathode bias resistor and all the heat it produces. This adds between 5 to 9% more power. Plus it improves the soundstage by making the instruments and voices bloom, making them more "3D".
 
Thank you, I ended up looking it up in another thread. I'm going to be under 2mv of ripple on b+ so I'm set. This amp/speaker pair should end up putting out around 110db of clean audio 1 meter away which is plenty loud. For private listening I don't usually go above 95 db.

I just realized we've been chatting around on two different threads, I'm thinking stay on this one with my updates etc.
 
Well, i actually made a SE 6l6 amp that was based on Keggar's schematic. Compared to the Alex Kitic design they both share the same qualities of very natural, dynamic, and realistic sound.
If you want to extract the most power from your amp you should install fixed bias. This has the advantage of deleting the large cathode bias resistor and all the heat it produces. This adds between 5 to 9% more power. Plus it improves the soundstage by making the instruments and voices bloom, making them more "3D".
Yeah, since I'm planning mono blocks mine will be aimed around the kt-120 tube. I almost want to go parallel and get about 22 watts or so. I do love some 3d sound, I may just have use fixed bias then. I've always heard that fixed bias had less of the "tube sound" which can mean a few different things but I cant knock it till I try it. This will be my first time building mono blocks and also using 2 chokes in the power supply so it should be pretty interesting. I ordered most of the components today and got two different bias resistors and a 5 watt 100 ohm pot to adjust the bias 50 ohms to tweak and roll other tubes.
 
I just realized we've been chatting around on two different threads, I'm thinking stay on this one with my updates etc.
That sounds good to me, probably will get a little more traffic that way anyways so maybe more questions will be answered. I'm going a little crazy with this build the more I think about it but I do want this one to be my daily driver.
 
If you are going to riff off of Kegmans scheme be sure to allow for changes to the component values to make sure your requirements are met. Tube circuits are much more forgiving than other systems and will work under a wide range of values. But it is hard to know if you are achieving your goals unless you do some measurements.
 
I'm going to do more research then throw it together and check the bias and voltages and throw it on the scope to check the sine wave and square wave output and sweep it for freq response, after that I will use an audio analyzer to check distortion vs output. Then of course spend time listening to it:)
 
If you are going to riff off of Kegmans scheme be sure to allow for changes to the component values to make sure your requirements are met. Tube circuits are much more forgiving than other systems and will work under a wide range of values. But it is hard to know if you are achieving your goals unless you do some measurements.
I'm actually am working on building a transistor preamp and it's going pretty well but only because I made sure to calculate everything out, I'm using it to drive the rh-84 and so far it sounds real nice and doesn't take away from the tube goodness at all but makes it even more full sounding. I will be building a tube preamp soon though hopefully.
 
I finished this amp a few weeks ago and can say that I believe the Blueglow hype. Best sounding amp I have heard. I used Kegger's schematic and Blueglow's info and layout. 6AQ8 preamp tube. Second power supply cap is nichicon 390uf 500v. Just ultralinear no triode and no volume control. I also JB welded a piece of aluminum down center of amp to increase chassis stiffness (output transformers are heavy) and for sheilding from power supply. Three holes through aluminum. 1 for high voltage. 1 for grounds. 1 for heaters. All my voltages are basically spot on with Blueglow's. Cannot think of a thing I would change. Thanks Kegger for the fantastic schematic! Know you are up there somewhere! Thanks Blueglow for all the wonderful videos and info!

IMG_3121.JPG IMG_3122.JPG IMG_3123.JPG IMG_3126.JPG
 
Wow, really nice build.

I've never used JB Weld, I didn't know you could just do that with a piece of aluminum. Pretty neat.

Only thing that concerned me was the electrolytic bypass caps on the cathode resistors. I assume that because they're chassis mount and high-wattage they don't get very hot?
 
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