Thanks for all the kind words. It was with all you guy’s help I’m listening to it today and I swear I am hearing stuff in familiar music I’ve never heard. Perhaps imagination but I think I will be connecting up the other amp and comparing. A quick question, is there any info on this forum on having the F5T with combo inputs balanced and rca?
Congratulations, man! I knew you were a stubborn stayer.
I’d take 6L6s recommendation, and enjoy the music a while before deciding whether to take it a step further or not. Might not be worth it.
Check out Nelsons living/listening room. I think he is quite happy with single ended
Cheers,
Andy
I’d take 6L6s recommendation, and enjoy the music a while before deciding whether to take it a step further or not. Might not be worth it.
Check out Nelsons living/listening room. I think he is quite happy with single ended
Cheers,
Andy
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Problem solved. Adding a transformer will not gain you anything except galvanic isolation, and if it’s already quiet, it’s not necessary.
Maybe you could add something like this if you really want to have the option to hook up balanced connections BTSB Buffer - SE/Bal to SE/Bal Buffer GB
There's a smaller panel-mount version of the same design too
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Hi guys, the reason for the inquiry about a balanced input is because I have a lot invested in cables. I borrowed a set of RCA’s from another system to test the F5T. If it was just ok, I would’ve said hey, it was a good time building it and perhaps on to the next. I really enjoyed doing the project, headaches and all. Very unexpectedly, the end result is extremely impressive. I have a set of balanced cables I’d like to use from my preamp to the F5T which is how this system was connected pre F5T. The borrowed RCA’s can go back on the system where they belong. Not only that but I use the full range RCA outputs on the preamp to feed the subs so there is no signal processing in 2 channel listening. I tweak the sub x-overs to compliment the towers. I really don’t want to buy y-splitters for this system and another set of RCA cables for the tube system because it only has RCA outs.
You could do what I did last year +, after I built my M2x, my MAC couldn't compete with the ACA's I built let alone the M2x. So I bought the parts for 2M DH Labs interconnects with RCA's, then I sold the MAC, and built an ALEPH J. ALEPH J has Balanced inputs, is single ended and has been the primary amp in my system.
I'm still building preamps and phono sections from the proceeds from the MAC, GREAT resale value!
I'm still building preamps and phono sections from the proceeds from the MAC, GREAT resale value!
Gonna listen to it and enjoy for a bit and really think it out. Thanks for the suggestion
to a007udio #1095
Hello a007udio,
I connected in my F5T (as well in all my other amp-builds) the speaker -(ground) to PSU - ground. I tried to keep the cable short. And I used a slightly bigger cable.
Most often 2.5mm² or 4mm²-speaker cable. I use screw terminals on my PSU-boards. It is often difficult to get more than 2.5mm² into the screw-terminals.
Greets
Dirk
Hello a007udio,
I connected in my F5T (as well in all my other amp-builds) the speaker -(ground) to PSU - ground. I tried to keep the cable short. And I used a slightly bigger cable.
Most often 2.5mm² or 4mm²-speaker cable. I use screw terminals on my PSU-boards. It is often difficult to get more than 2.5mm² into the screw-terminals.
Greets
Dirk
The feedback voltage is sampled at the output node on the FE the board. Since all voltage must be sampled between two points, the second point should be as close to the actual feedback resistor as possible.
Additional wiring to the power supply boards presents two issues, one is the added inductance of the extra wire, and the other is mixing of clean and dirty grounds in the feedback signal.
While anyone is free to connect it anywhere, there is some technical benefits to keeping the feedback loop (which includes the speaker return lead) as short as possible. For a low NFB amplifier like the F5/T it's probably not critical, but best practices are a good thing to follow.
The word 'Ground' is probably the worst misnomer in all of engineering, it doesn't actually exist except in theory. Think about it in terms of voltages and currents.
Additional wiring to the power supply boards presents two issues, one is the added inductance of the extra wire, and the other is mixing of clean and dirty grounds in the feedback signal.
While anyone is free to connect it anywhere, there is some technical benefits to keeping the feedback loop (which includes the speaker return lead) as short as possible. For a low NFB amplifier like the F5/T it's probably not critical, but best practices are a good thing to follow.
The word 'Ground' is probably the worst misnomer in all of engineering, it doesn't actually exist except in theory. Think about it in terms of voltages and currents.
So testing V1.5 with 2trans per half and cascaded input trans. Running 1.35 amps per output transistor. everything looks stable and playing music through old Epos bookshelf. Sounds very good. My heatsinks are at 55c and the IRFP9240 package temp is 78c at the same point as thermistor. Do those temps seem ok. Been running there for 8.5 hrs.
