My offer are LDA ultra low distortion amplifier DiY kits at a non-profit price until further notice. I've advertised them at a few European Ebay sites so far.
Condition for non-profit price: send me photos of the completed amp that I can post on my homepage.
All kind of distortions are surely much lower than what can be sensed by human hearing (e.g. 1kHz THD<0.001%). Several prototypes were built and all function perfectly. ABX blind tests and nulltest. No "sound of its own", neutral and transparent. Can be used as reference amplifier or measurement amplifier, too.
LDA MIN: 2x80 Watts stereo with turn-on thump muting via a mechanical relay (mechanical relays may somewhat degrade distortion), no protections. 75 EUR + shipping.
LDA DM1: 2x120 Watts dual mono with full protections via ultra low distortion solid state relays. 140 EUR + shipping.
LDA DM2: 2x200 Watts dual mono with full protections via ultra low distortion solid state relays. 178 EUR + shipping.
LDA MON: 1x200 Watts mono with full protections via an ultra low distortion solid state relay. 90 EUR + shipping.
All components are from reliable source. Critical components are from renowned manufacturers.
Outside of Europe shipping costs may be prohibitive. The above prices include Ebay commission and currency conversion by Paypal. Currently on Ebay in the UK, Germany, France, Spain, Italy. If you're interested and the kit is not listed on the Ebay of your country, please write me a private message.
More information: Euraudio
LDA home
Please check what is included in the kits and what is not.
Condition for non-profit price: send me photos of the completed amp that I can post on my homepage.
All kind of distortions are surely much lower than what can be sensed by human hearing (e.g. 1kHz THD<0.001%). Several prototypes were built and all function perfectly. ABX blind tests and nulltest. No "sound of its own", neutral and transparent. Can be used as reference amplifier or measurement amplifier, too.
LDA MIN: 2x80 Watts stereo with turn-on thump muting via a mechanical relay (mechanical relays may somewhat degrade distortion), no protections. 75 EUR + shipping.
LDA DM1: 2x120 Watts dual mono with full protections via ultra low distortion solid state relays. 140 EUR + shipping.
LDA DM2: 2x200 Watts dual mono with full protections via ultra low distortion solid state relays. 178 EUR + shipping.
LDA MON: 1x200 Watts mono with full protections via an ultra low distortion solid state relay. 90 EUR + shipping.
All components are from reliable source. Critical components are from renowned manufacturers.
Outside of Europe shipping costs may be prohibitive. The above prices include Ebay commission and currency conversion by Paypal. Currently on Ebay in the UK, Germany, France, Spain, Italy. If you're interested and the kit is not listed on the Ebay of your country, please write me a private message.
More information: Euraudio
LDA home
Please check what is included in the kits and what is not.
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Hello, ga77a,
Well, I suggest you start with a simpler DiY amplifier. Although there are very detailed online assembly instructions for each PCB in LDA kits, I really don't advise for stark beginners to buy these kits.
Also, FYI, the kits don't contain the PCB necessary for mains input and distribution. There is a readily designed KiCAD PCB file available in the online help files for this purpose, but everybody should use this PCB at their own risk. There are safety standards for equipment using line voltage, and I don't own a copy. So I designed the line input board by "common sense", and I'm in good faith that it is safe enough, but it may not comply with safety standards effective in your country.
Well, I suggest you start with a simpler DiY amplifier. Although there are very detailed online assembly instructions for each PCB in LDA kits, I really don't advise for stark beginners to buy these kits.
Also, FYI, the kits don't contain the PCB necessary for mains input and distribution. There is a readily designed KiCAD PCB file available in the online help files for this purpose, but everybody should use this PCB at their own risk. There are safety standards for equipment using line voltage, and I don't own a copy. So I designed the line input board by "common sense", and I'm in good faith that it is safe enough, but it may not comply with safety standards effective in your country.
ultra low distortion
A nulltest has proved that this amplifier has no audible distortion. Nulltest difference file can be downloaded near the end of the following page: The LDA low distortion audio power amplifier project
The ultra low distortion can be spoiled by changing two resistors, and so a distortion profile similar to that of tube amplifiers will result (see 4th attached image).
A nulltest has proved that this amplifier has no audible distortion. Nulltest difference file can be downloaded near the end of the following page: The LDA low distortion audio power amplifier project
The ultra low distortion can be spoiled by changing two resistors, and so a distortion profile similar to that of tube amplifiers will result (see 4th attached image).
Attachments
Built 6 prototypes for extensive testing, all function perfectly. So far, one customer built an LDA MIN and he was impressed with the sound quality.
1kHz TH Distortion depends on ideally routing cables and wires, but it was below 0.001% on all the prorotypes (depends somewhat on power level and load impedance). TIM below 0.005%.
Is there anything better on a gloomy fall evening than soldering components?
1kHz TH Distortion depends on ideally routing cables and wires, but it was below 0.001% on all the prorotypes (depends somewhat on power level and load impedance). TIM below 0.005%.
Is there anything better on a gloomy fall evening than soldering components?
Conditions for 20% off
Until further notice:
I will refund 20% of the above non-profit price if you send me images of your completed amp (inside and outside) within 6 months of the purchase of the kit. You must have a PayPal account to which I can send the money back.
So essentially you can get these kits at 80% of the non-profit price now until I recall this offer.
(FYI: the non-rofit price is: components cost + a small fee for sorting and packaging the components + Ebay commission + Paypal currency exchange fee.)
Until further notice:
I will refund 20% of the above non-profit price if you send me images of your completed amp (inside and outside) within 6 months of the purchase of the kit. You must have a PayPal account to which I can send the money back.
So essentially you can get these kits at 80% of the non-profit price now until I recall this offer.
(FYI: the non-rofit price is: components cost + a small fee for sorting and packaging the components + Ebay commission + Paypal currency exchange fee.)
sale changed: 20% or EUR 20 off (whichever is smaller)
Sale condition changed:
I will refund 20% or EUR 20 (whichever is smaller) of the above non-profit price if you send me images of your completed amp (inside and outside) within 6 months of the purchase of the kit. You must have a PayPal account to which I can send the money back.
Sale condition changed:
I will refund 20% or EUR 20 (whichever is smaller) of the above non-profit price if you send me images of your completed amp (inside and outside) within 6 months of the purchase of the kit. You must have a PayPal account to which I can send the money back.
Sorry, I had an awful lot of problems shipping a package to the UK, because of the forms to fill out for customs and so on, further the customs raise the price so high, it is not economic. So i decided not to ship to the UK. It's not worth the hassle. I believe there are many good amplifier kits available in the UK. I'm sure that even if a kit happens to have as many as 20 times higher distortion than the LDA MIN, it is still not audible for the human ear.
If 2x50 Watts is enough for you, then I have a newer and much cheaper kit, called CTA MIN, which is a max. 2x50 Watts amplifier, with only 2...3 times higher distortion than the LDA MIN. The CTA MIN fits in an envelope, so I hope I can send it as an air mail letter, without need for customs declaration. The price of the CTA MIN on Ebay is 36 EUR + 10 EUR air mail postage. Recalculate it to GBP. I have only 1 CTA MIN kit right now on stock. If you want it, I can list it on the UK Ebay, because currently it is only listed in Germany, Italy and France. Further information: http://euraudio.dx.am/en/amp/CTA/CTA_home_en.html
If 2x50 Watts is enough for you, then I have a newer and much cheaper kit, called CTA MIN, which is a max. 2x50 Watts amplifier, with only 2...3 times higher distortion than the LDA MIN. The CTA MIN fits in an envelope, so I hope I can send it as an air mail letter, without need for customs declaration. The price of the CTA MIN on Ebay is 36 EUR + 10 EUR air mail postage. Recalculate it to GBP. I have only 1 CTA MIN kit right now on stock. If you want it, I can list it on the UK Ebay, because currently it is only listed in Germany, Italy and France. Further information: http://euraudio.dx.am/en/amp/CTA/CTA_home_en.html
No problem, I understand! I am interested in the CTA MIN kit, Could you link to the ebay.ft listing? I could not find it. When you say you have 1x kit left, that's enough for 2 channels or for 1? Thanks!
Thank you for your interest in CTA MIN. It's 2 channels stereo. You meant ebay.fr? Here's the link: https://www.ebay.fr/itm/195114069682
If you're located in Scotland, you may not be able to order the kit from the French Ebay. because this is shipping from aboroad to France only. Try to order on the French Ebay, but if I need to list the kit on the UK Ebay, pls come back and tell me.
If you're located in Scotland, you may not be able to order the kit from the French Ebay. because this is shipping from aboroad to France only. Try to order on the French Ebay, but if I need to list the kit on the UK Ebay, pls come back and tell me.
Here's the UK listing if you're in Scotland, pls use this: https://www.ebay.co.uk/itm/195186962371