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Old 21st November 2008, 07:29 PM   #1
DC2100 is offline DC2100  United Kingdom
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Question Latest incarnation of music angel kt88

Hi, I have been reading posts everywhere regarding this amp and it appears to be quite popular for obvious reasons. I was wondering if it would be handy to have all the info in one place rather than jumping from thread to thread, forum to forum. The problem for me is the many diff. revisions, I have one of the later models bought about 1 month ago and it appears they have had a stab at implementing quite a few of the mods from the Lampizator website, (coincidence?) see my pics. I have done the triode conversion, removed the 22k input that was actually 100k (seems they like that value!) and shorted one resister as they have removed it from the opposite channel anyway, good quality control! I have removed the cathode bypass caps too, (I have read pros and cons so I wanted to hear for myself) Oh and I removed R1-R4 then re-set the bias. (still 10r under pcb, I had way too much voltage after doing lampys mods) But they have removed a lot of resistors, added vishay and wima caps and they have even re designed the circuit board/s. I have to confess this is my first valve amp and I am a complete novice compared to most here but I love modifying equipment and listening to the results good or bad.
Anyway for anyone like me thinking of doing the mods, here is my findings. After switch on there was an increasing hum, transformer noise and the bias just went through the roof, so much I had to keep turning off the amp, now if youve never done this before, like me, you wont know that you cant turn the pots the same way to lower the voltage, as you can see from my pics 2 are clockwise and 2 are counter clockwise, I had to find out the hard way! In the end I removed the valves and dropped the voltage on the pre-sets. I managed to sort the bias but I still had too much noise so I started putting it back to square 1, replacing, removing then checking each stage, if it didnt improve I left it off. Replacing the feedback helped but I dont know why, the biggest bug was the short across the 47k underneath, nearly all the other mods have been done in circuit by the manufacturer so they are definitely listening! Other mods they have done is the B+ no longer comes from R13, see pic. If anyone would like the Hi Res versions for cross ref then please msg me.
I would like to hard wire this amp but its too difficult for me at present, there are no R or C labels on the board and absolutely nothing matches the value printed, my grid stoppers are 1 meg even though it says 560k. I also seem to have 485v at the small tube bases, I dare not even turn it on now looking at the value of the caps, 315-400 volts. I intend to fit resistors across them all but I fear there may be a problem elsewhere, as you can see from my markings I have removed and measured some of the resistors and the lytics, (one has had a bulge since new and I intend to replace them) but they seem fine. My problem if someone can help apart from the over voltage is how to rewire using as much of the parts as poss, there isnt a lot of room to re do the power supplies which I see as been the major issue. I would like to keep the cost down as this is a complete learning curve for me, getting decent sound is going to be a bonus! Hopefully we can collate enough info to help anyone like me that wants to have a go but I cannot stress enough that you read this first. Safety Practices, General and Ultra-High Voltage
If you are still awake then here's my pics, good start, can only seem to load 1?
Attached Images
File Type: jpg angel 1 resize.jpg (85.9 KB, 1165 views)
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Old 24th November 2008, 01:11 AM   #2
DC2100 is offline DC2100  United Kingdom
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Jeesus, now i know what its like to be a lepper, apart from loosing parts of my anatomy anyway.
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Old 24th November 2008, 04:06 PM   #3
budkor is offline budkor  United Kingdom
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Default Xd800 Kt88

I have had this amp for about 2 months, and it is a winner. It sounds absolutely fantastic. It is better sounding amp than any amp I have had and heard.

Only thing is I am wondering if I must start thinking about doing mods and upgrades - as it may even better after mods.

I am a newbie on valve amps, so this is a problem. Should I let some engineers do it for me, or do it by myself reading up and learning about valve DIYs.

The set is not having any problems right now apart from I can hear very slight buzz when music is not playing. I must bring my ears close to the speakers to hear the buzz, so this is not really problem for me.

Anyhow I am looking forward to getting and sharing more info about this excellent amp.

Thanks
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Old 24th November 2008, 04:45 PM   #4
budkor is offline budkor  United Kingdom
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Default XD800 KT88

I would appreciate any comments or information regarding this amp from the fellow amp owners, tube DIYers and tube specialists.

Thanks
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Old 24th November 2008, 08:15 PM   #5
DC2100 is offline DC2100  United Kingdom
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Default Re: Xd800 Kt88

Quote:
Originally posted by budkor
I have had this amp for about 2 months, and it is a winner. It sounds absolutely fantastic. It is better sounding amp than any amp I have had and heard.

Only thing is I am wondering if I must start thinking about doing mods and upgrades - as it may even better after mods.

I am a newbie on valve amps, so this is a problem. Should I let some engineers do it for me, or do it by myself reading up and learning about valve DIYs.

The set is not having any problems right now apart from I can hear very slight buzz when music is not playing. I must bring my ears close to the speakers to hear the buzz, so this is not really problem for me.

Anyhow I am looking forward to getting and sharing more info about this excellent amp.

Thanks

Hi Budkor, I am affraid I do not share your enthusiasm for the sound quality of this amp! I do believe that this is a bargain though and I do believe it can be improved because in my experiance everything is either built to a cost or like some of these not built properly! I did not have any probs with noise. Regarding your question of wether you should try to mod? I dont think anyone can answer that but you. Have you checked out this? http://www.lampizator.eu/AMPLIFIERS/...reworking.html
I would say if you have never worked on live equipment before or you dont know how to discharge a circuit then maybe 480volts is not a good project to start with.
I have no engineering background but I have always loved taking things apart and trying to improve them, from my first motorbike, Air Rifle, to every single piece of hifi I have ever owned in 20 years. I found that if you build somthing from scratch then its a lot easyer to fix if it goes wrong and you learn a lot on the way.
Getting back to the Music Angel, I found it had VERY deep base but I have been informed that 'valves do that' In pentode mode I found it very hard and spitty, god knows why anyone would want to? or maybe my speakers are a difficult load? Now some are going to say, (maybe) that in pentode its got more power so it should handle the load better? Well with my speakers, 2x jordan jx125 4x jordan jx52 per side and my cable, electrofluidics monolith, the amp actually screamed and a kt valve turned blue! I used another pair of speakers with the same monolith to try the pentode/triode operation and it was night and day, pentode SUCKS! Apart from the deep base my big disapointment was the upper registers, its severely lacking in soundstage in my set-up, treble seems rolled off, focus is poor and its 2 dimentional. I say all of this but I am still think its a bargain and I really like it, I am probably been a bit unfair as the amp has barely played a full CD, such is my enthusiasm to tweek. I am looking forward to ripping it to bits!
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Old 24th November 2008, 08:56 PM   #6
budkor is offline budkor  United Kingdom
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Default Hi DC2100

Thanks for your comment. Interesting.

Well my electronics DIY skill is limited to having built 7TR radio kit on my high school time with solder iron and ohm meter. But the kit never worked, and I ended up taking it to the local radio shop, and the guy there fixed it for me. I felt a bit disappointed with my skills and never done DIY again. So maybe it is wise for me to get someone else to mod and upgrade, if needed.

I am listening to Pink Floyd CD now through Music Angel, Arcam CDP and Tannoy 607, and it sounds fantastic. It is dynamic, clear, detailed in top, mid and bottom. Powerful controlled bass, fast and transparent and 3 dimensional sound coming out there. It is the first class performance.

I have tried with different speakers, and must admit the XD800 sounds a lot better with older and efficient speakers. It does not like KEFs and Yamaha. It seem to like Epos and older speakers, but the Tannoy 607 sounds the best, which I am using now.
So speaker matching seems affecting on sound performance, but maybe this is subjective issue, as some folks prefer warm and vintage sound, while others like fast and hard sound.

However, I don't think I will venture into DIYing, as I have not any tools or knowledge right now anyway, and I can see that it certainly is not like painting your windows or wall papering DIY :-)
I have a local friend who is an electronic engineer, so I will ask him to do it for me, or maybe just trade in for something else (I would like to try NAIM 250 :-)) later on.

I have had a few valve amps (starting from Rogers Cadet, which was smoking fumes from the oil caps in the middle of playing CD, and almost started house fire x-(...), and Norh SE9 (which is a great amp - I use mainly night listening sessions). But this XD800 is the best soudning and most powerful one. I could not put the volume past 9 o'clock position, as it gets far too loud past that.

Please let us know how you get on with the ripping the XD800, and how it improves.

Thanks & Regards
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Old 26th January 2009, 03:32 PM   #7
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Cool KT88 Mods

I also recently aquired one of these amps and it works well. I also decided to see if I could improve the sound. I downloaded the images and files from the lampizator site only to find that my amp already appeared to have some of the mods done. There are some odd things about it and the right and left chanels appear different. I decided to proceed with caution and so I just replaced the capacitors (the white ones) with audio grade PIO replacements and I could hear an improvement straight away. I then did the same t the red ones and the sound was not so good. Needless to say, I replaced he red ones. I might try some more of the mods later but need to understand more about what they have done before I start ripping stuff out as suggested on the lampizator site. Interesting though.
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Old 26th January 2009, 05:50 PM   #8
DawgNo1 is offline DawgNo1  United Kingdom
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Hi friezewood, I found exactly the same but went ahead and did lampys mods, I would recomend you do them 1 at a time and not all at once, I think the circuit may be different because when I put it back together it didnt work very well. I couldnt find anything wrong so I had to take it to someone who knows what they are doing! The guy has 50 years exp with hifi and valves and he does it for a living. I dont feel too bad because he hasnt fixed it yet, he put it all back to how it should be according to the schematic and it still doesnt function correctly. Keep us posted on your mods, I will hopefully be getting mine back soon, I will be taking more time with it!

Oh ive just noticed Ive got 2 usernames, must be getting scenile in my old age I started the thread off as DC2100....

Alan
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Old 28th January 2009, 11:35 PM   #9
toufu is offline toufu  United States
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I did the lampizator mod to my Music Angel... And I think it sounds better now.. :-) Anyways, it's much louder, and has more details and clarity and less warmth and muddiness. Let me know if you have any questions.
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Old 21st August 2013, 09:20 PM   #10
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Hello world!
I am new in the forum and hope to exchange some experience about the Music Angel :-)

I recently biased the tubes. But there are 6 trimpots. I turned 2 of them to find out that these were not the ones to bias the tubes
Then, I found the corresponding tubes for the other 4 trimpots.
However I had turned these 2 previously and don't know what they do, where to check the value and which value it should be :-(
Could you help me?
Many thanks in advance!

Abou the amp, in my opinion it's a good value for money so far.

Regards,
Dieter.
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