I want to build a relatively low power and very much all in one tube amp kit. I really like the K-12G from what I have read, but there appear to be a lot of mods done to pull it up to optimal performance. I am also looking at the K-502 but unfortunately there doesn't appear to be a lot of documentation on those builds. Does the K-502 address any of the issues people are modding the K-12G to fix???
I am wondering if I am better off getting the K-12G and spending the time getting different caps, adding snubbers, changing the tranfo, etc. or just getting the K-502 and maybe changing the pot and just upgrading the caps.
The speakers I am buying to go with this are the Klipsch RB-61's which have high enough sensitivity for me (> 94 dB), especially for a small apartment bedroom.
I am wondering if I am better off getting the K-12G and spending the time getting different caps, adding snubbers, changing the tranfo, etc. or just getting the K-502 and maybe changing the pot and just upgrading the caps.
The speakers I am buying to go with this are the Klipsch RB-61's which have high enough sensitivity for me (> 94 dB), especially for a small apartment bedroom.
Whether a person has the K-12G or the K502, upgrading would be virtually the same and IMHO probably follow the usual upgrade path for any valve amp.
It seems to me that the real choice here is whether you want to use the 10GV8 tube or the 11BM8 tube.
It seems to me that the real choice here is whether you want to use the 10GV8 tube or the 11BM8 tube.
Seeing as this is the case, which in your opinion is the better of the two? I am now leaning to the K-502.
There are PP schematics available out there for the 6BM8 which could be tried point to point using the same iron and most of the components of the K502, not sure the same can be said of the K-12G.
Personally i'd get 2 of these More Info for item K-501
dave
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dave
this is the mono version. The key is twice the power supply (same power stransformer as the other, but you get 2 of them).
dave
dave
Right now I am doing my best to keep this compact and all in one as it were. Given that I plan to upgrade the caps and OPT, I am now leaning very heavily towards the K-502. If I don't order soon, I'll never build :/
Great idea from Dave!
That separate PS is really a boon to better sonics, and well worth the extra few $ as you really do get twice the PS. That really small single PS transformer is really on the small side for stereo. Will really help lower distortion. Just park them side by side and not much bigger. Stereo separation is improved too. Great idea that you won't regret! Probably as good as upgrading output transformers in this case!
That separate PS is really a boon to better sonics, and well worth the extra few $ as you really do get twice the PS. That really small single PS transformer is really on the small side for stereo. Will really help lower distortion. Just park them side by side and not much bigger. Stereo separation is improved too. Great idea that you won't regret! Probably as good as upgrading output transformers in this case!
Interesting idea. I'm doing my very best to keep this as compact as possible 🙁. What are your thoughts on maybe instead just buying a beefed up tranfo for the stereo amp? Part of my worry is the cost of upgrading the parts on two boards, especially if I use high quality caps, not to mention twice the initial cost.
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Not as effective as 2.
Except for thw parts in the power supply that are duplicated 2 mono boards will have exactly thge same parts as the stereo board
Dual mono is $45 more than the stereo. And you have immediately upgraded the transformers & power supply capacitance.
dave
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Maybe just get monoblocks for an improvement and sell them when you want to upgrade, but you'll loose big time when you sell. Or build the later amp kit now and won't loose any $ if you really want all upgrades. To bad you can't breadboard simple circuit as it wouldn't cost more than $300-350 with upraded parts.
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All right, all right. Looking at the fact that I will in fact have a bigger PS as well as upgraded tranfo...final verdict is in favor of dual K-501. That being said, do you think I will be fine with regards to not upgrading the caps? Also, any suggestions for a really solid stereo pot for this rig?
Caps and pot mods you mentioned earlier can't hurt! One advantage of caps upgrade now is it was mentioned it was easy to lift traces on circuit board when replacing parts. Maybe the same for the pots. But then again you may want to try and let it break in and see how much difference you get with mods.
Fair enough as well. However, I want these to have one pot to control the whole stereo. Thoughts on the most efficient attenuators in terms of money vs. performance? This will most likely be the only initial mod.
Built mine as stock and it sounded OK, after about 30 hours of play I was convinced there was an improvement, perhaps it had "burnt in".
Wanting to learn more about the effect a pot has on the signal I carried out a simple experiment. Through use my amp became set at my ideal listening level so I measured the resistance either side of the wiper. I replaced the pot with equivalent resistors. I reasoned that as long as the resistors were of good quality then this set up would be equal to one step of an expensive stepped attenuator.
I'm afraid my sad old ears couldn't detect any significant upgrade......🙁
Fair enough. I'm ordering the two K-501's soon and will build stock and just run it from a headphone to RCA jack cord. However, is anyone else concerned with the lack of EMI filter off the mains power cord as well as the lack of a 3 prong cord which could easily be grounded to the tranfo frame?
The K501 might using the 11MS8 tubes so is more like half of a K-12M not K502, might be worth checking....😉
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