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Post by karma67 on Mar 19, 2020 18:37:20 GMT
an interesting one, ive just replaced my gec kt88's (quad) with sovtek kt88's. now i know the gec's are supposed to be the holy grail of kt88's and command huge sums but im not hearing a huge drop in the sound,infact the sovteks seem to have a bit more omph to them,there is a subtle difference in clarity in favour of the gec's at the moment but the sovteks need some hours on them. alan i believed you tested these sovteks i bought them from ian.
the price difference is 4 gec's £1000+ and the sovteks were £90! do different brand power valves really make that much difference to the sound,at the moment i think not. |
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Bigman80
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Post by Bigman80 on Mar 19, 2020 18:56:44 GMT
an interesting one, ive just replaced my gec kt88's (quad) with sovtek kt88's. now i know the gec's are supposed to be the holy grail of kt88's and command huge sums but im not hearing a huge drop in the sound,infact the sovteks seem to have a bit more omph to them,there is a subtle difference in clarity in favour of the gec's at the moment but the sovteks need some hours on them. alan i believed you tested these sovteks i bought them from ian.
the price difference is 4 gec's £1000+ and the sovteks were £90! do different brand power valves really make that much difference to the sound,at the moment i think not. A lot of this depends on the circuit. The BB phonostage is quite sensitive to the valves inside and you can pretty much tailor the sound to what you like, bit the Jolida didnt seem to care one iota what was in, but the design was very different. Had some varied responses from valve kit so I'd suggest that in your JW amp, it may not be all that critical. |
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Post by karma67 on Mar 19, 2020 19:05:29 GMT
an interesting one, ive just replaced my gec kt88's (quad) with sovtek kt88's. now i know the gec's are supposed to be the holy grail of kt88's and command huge sums but im not hearing a huge drop in the sound,infact the sovteks seem to have a bit more omph to them,there is a subtle difference in clarity in favour of the gec's at the moment but the sovteks need some hours on them. alan i believed you tested these sovteks i bought them from ian.
the price difference is 4 gec's £1000+ and the sovteks were £90! do different brand power valves really make that much difference to the sound,at the moment i think not. A lot of this depends on the circuit. The BB phonostage is quite sensitive to the valves inside and you can pretty much tailor the sound to what you like, bit the Jolida didnt seem to care one iota what was in, but the design was very different. Had some varied responses from valve kit so I'd suggest that in your JW amp, it may not be all that critical. the biggest differences with this amp have come from changing the ecc81's |
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Bigman80
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Post by Bigman80 on Mar 19, 2020 19:24:08 GMT
A lot of this depends on the circuit. The BB phonostage is quite sensitive to the valves inside and you can pretty much tailor the sound to what you like, bit the Jolida didnt seem to care one iota what was in, but the design was very different. Had some varied responses from valve kit so I'd suggest that in your JW amp, it may not be all that critical. the biggest differences with this amp have come from changing the ecc81's Ok....so its responsive to changing valves, which does seem to suggest there isn't a great deal in the KT88s |
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Post by Deleted on Mar 19, 2020 20:20:37 GMT
Not necessarily as the ecc81s do a totally different job and different part of the circuit.
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Post by rexton on Mar 19, 2020 21:19:48 GMT
Tried Sovtek's didn't rate them. I ended up with the Genelex Gold Lions, they've seen off quite a few differing KT88's.
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Post by Deleted on Jun 18, 2020 6:35:59 GMT
I do recommend trying KR KT88s. In my opinion those are the only today made 88s which are up to the game. Not only comparable to GECs but also outperforming them in certain departments, like rhythmic perfection or extending fq on both ends and better grip on bass too. We are distributing KR in thw UK and these are my number 3 selling tube, right after 300B( which is also exquisite ) and 5U4g rectifier.
None of them on stock BTW, which says it all. We need tobre stock after thus closing period.
KT88 awareness is growing in case of KR and Ibserved many owners whose GECs passes away.
Getting new is almost impossible, well measuring ones, doesn't matter how expensive they can still die on your hands and with no warranty it is just a lost of money.
KR KT88 coming with std 2y warranty, just FYI.
Price RRP is £ 360 for a pair and £ 720 for the Quad, factory matched in KRs red giftbox.
If there is higher demand here anong the forum users qe can always create a group buy with the preferential price.
KR is also making KT 150, for those power hungry ones. Both tubes had been given higly recommended budge by prestigious Japanase Hi-End magazine.
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Bigman80
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Post by Bigman80 on Jun 18, 2020 6:39:59 GMT
I do recommned trying KR KT88s. In my opinion those are the only today made 88s which are up to the game. Not only comparable to GECs but also outperforming them in certain departments, like rhythmic perfection or extending fq on both ends and better grip on bass too. We are distributing KR in thw UK and these are my number 3 selling tube, right after 300B( which is also exquisite ) and 5U4g rectifier. None of them on stock BTW, which says it all. We need tobre stock after thus closing period. KT88 awareness is growing in case of KR and Ibserved many owners whose GECs passes away. Getting new is almost impossible, well measuring ones, doesn't matter how expensive they can still die on your hands and with no warranty it is just a lost of money. KR KT88 coming with std 2y warranty, just FYI. Price RRP is £ 360 for a pair and £ 720 for the Quad, factory matched in KRs red giftbox. If there is higher demand here anong the forum users qe can always create a group buy with the preferential price. KR is also making KT 150, for those power hungry ones. Both tubes had been given higly recommended budge by prestigious Japanase Hi-End magazine. Am I right in thinking these are around £700? Valves are getting to crazy prices aren't they! |
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Post by Deleted on Jun 18, 2020 6:55:30 GMT
I do recommned trying KR KT88s. In my opinion those are the only today made 88s which are up to the game. Not only comparable to GECs but also outperforming them in certain departments, like rhythmic perfection or extending fq on both ends and better grip on bass too. We are distributing KR in thw UK and these are my number 3 selling tube, right after 300B( which is also exquisite ) and 5U4g rectifier. None of them on stock BTW, which says it all. We need to re stock after thus closing period. KT88 awareness is growing in case of KR and I served many owners whose GECs passes away. Getting new is almost impossible, well measuring ones, doesn't matter how expensive they can still die on your hands and with no warranty it is just a lost of money. KR KT88 coming with std 2y warranty, just FYI. Price RRP is £ 360 for a pair and £ 720 for the Quad, factory matched in KRs red giftbox. If there is higher demand here among the forum users we can always create a group buy with the preferential price. KR is also making KT 150, for those power hungry ones. Both tubes had been given highly recommended budge by prestigious Japanese Hi-End magazine. Am I right in thinking these are around £700? Valves are getting to crazy prices aren't they! They used to be £ 680, but with Blowjob and company ruining the UK industry, plus insane increase of the transport prices related to pandemic the current prices are just as I stated. Sadly, as profit gone down, not grown and all that money just goes to the usual middle man, meaning banksters and courier corporations. Those last comfortably for themselves even removed glass objects from insurance, so extra spending for protective materials and overpay for the size of boxes are adding to the prices, as insurance buys you nothing here , it is just give away on top. Some pictures  |
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Bigman80
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Post by Bigman80 on Jun 18, 2020 7:01:58 GMT
Am I right in thinking these are around £700? Valves are getting to crazy prices aren't they! They used to be £ 680, but with Blowjob and company ruining the UK industry, plus insane increase of the transport prices related to pandemic the current prices are just as I stated. Sadly, as profit gone down, not grown and all that money just goes to the usual middle man, meaning banksters and courier corporations. Those last comfortably for themselves even removed glass objects from insurance, so extra spending for protective materials and overpay for the size of boxes are adding to the prices, as insurance buys you nothing here , it is just give away on top. Some pictures Nice looking things aren't they. |
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Post by Deleted on Jun 18, 2020 9:52:15 GMT
Bear in mi d that not all manufacturers use exactly the same blend of materials in the anode, cathode, grid, screen grid, ect, and that the topology of the amp may mean that the 88 is triode strapped rather than being used as a tetrode.
And that the triode curves from different manufacturers are not necessarily the same. Using one manufacturers valve with the set current and voltage in the amp may put its operating point in a different place on the curves than it does on another manufacturers curves.
This could mean that the thd stays pretty much the same, but the thd is made up of even order and odd order distortion. The balance between even and odd order harmonics may change, meaning it sounds different. More odd order such as 3rd or 5th will tend to a sharper sound in my experience, more 2nd will tend towards a more lush sound.
There are lots of other reasons why they might sound different, and there is no real way to tell until you try them. Gec kt88s may be the golden egg in one amp, and sound awful in another. Same for any of them. Look at the dissipation figures too, older production valves usually have lower dissipation figures than new production ones, you need to make sure that you aren't running the valves flat out at the top end of this figure. This can vary quite a lot, you can have older stuff with a max of say 25w dissipation and modern production variants with say 30. If an amp is designed to run at 28 w max, you don't want to be putting the old one's in it, eventually there might be a big bang.
So don't expect old and new to be strictly interchangeable, and if you are planning to spend huge money, make damn sure that you aren't going to lunch a quad of 88s ect by just assuming that a valve is a valve is a valve. They aren't.
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Post by Deleted on Jun 18, 2020 10:00:02 GMT
Bear in mi d that not all manufacturers use exactly the same blend of materials in the anode, cathode, grid, screen grid, ect, and that the topology of the amp may mean that the 88 is triode strapped rather than being used as a tetrode. And that the triode curves from different manufacturers are not necessarily the same. Using one manufacturers valve with the set current and voltage in the amp may put its operating point in a different place on the curves than it does on another manufacturers curves. This could mean that the thd stays pretty much the same, but the thd is made up of even order and odd order distortion. The balance between even and odd order harmonics may change, meaning it sounds different. More odd order such as 3rd or 5th will tend to a sharper sound in my experience, more 2nd will tend towards a more lush sound. There are lots of other reasons why they might sound different, and there is no real way to tell until you try them. Gec kt88s may be the golden egg in one amp, and sound awful in another. Same for any of them. Look at the dissipation figures too, older production valves usually have lower dissipation figures than new production ones, you need to make sure that you aren't running the valves flat out at the top end of this figure. This can vary quite a lot, you can have older stuff with a max of say 25w dissipation and modern production variants with say 30. If an amp is designed to run at 28 w max, you don't want to be putting the old one's in it, eventually there might be a big bang. So don't expect old and new to be strictly interchangeable, and if you are planning to spend huge money, make damn sure that you aren't going to lunch a quad of 88s ect by just assuming that a valve is a valve is a valve. They aren't. Well said Ant, the fact is that visiting people I have seen many times such a flowers that you wouldn't believe if I told you. Don't have to add I guess that all those chaps are believing they are highly experienced and ate their teeth in that hobby and are not prepared for being advised and whatever you say may be used against you, so better keep quiet  |
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Post by Deleted on Jun 18, 2020 10:19:58 GMT
I don't build amps any more, last one I did was about 5 years ago. I realised that I know enough to know that I don't know enough.
These days I stick to other things.
With any electronics design there are so many things to take into account and everything is a balance. Upsetting the balance the designer chose is where problems can occur
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Post by Deleted on Jun 18, 2020 10:23:46 GMT
I don't build amps any more, last one I did was about 5 years ago. I realised that I know enough to know that I don't know enough. These days I stick to other things. With any electronics design there are so many things to take into account and everything is a balance. Upsetting the balance the designer chose is where problems can occur Exactly what I might have say about my own DIY history. I enjoyed the learning process and the hobby and learned a lot. Build quite a few good amps and speakers, which are still beloved by the owners and I had a lot of great time and joy doing it. The rest as they say is a HISTORY |
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