DIY-GENE A700 Mark Levinson Clone

Andy5112405 · 27th May 2011, 11:45 AM

Having built one of these "Clones" I have a few words of warning.

The design is very robust and the build quality is good. However, the DIY spirit is poor and the supply very poor.

My A700 Kit arrived from Hong Kong wrapped in newspaper and sheets of cardboard. The amplifier boards come pre-assembled and tested, they also arrived pre-stressed and most of the transistors bent well away from their natural angle. Several of the power transistor leads had broken away from their PCB lands, however, the PCB had mercifully not been damaged. Several of the taller capacitors had been punctured and two of the small ceramic caps had disappeared (OK the legs were still there) - All down to the appaulling packaging.

After a bit of cajoulling, DIY-GENE replaced the faulty components. They were nice enough about the whole polava but after spending many hundreds of pounds on the kit I was anxious to get it going.

Don't expect any technical help from these guys, it just aint forthcoming.

The kit I received was supplied with SIL-PAD insulators and was biassed at 1.26A.

The supplied heatsinks are completely incapable of operating at these levels. After a few days of operation one channel detonated (literally blowing transistor fragments around the amplifier).

As a minimum, throw away the SIL-PADs and invest in MICA and GOO. Even this resulted in excessive heatsink temperatures. I eventually had to crank down the bias to 1.0A (ie Class AB operation at high volume) in order to maintain any sort of reliability.

OK, I didn't spend the extra cash on purchasing the recommended 42-0-42V transformers, mine are 45-0-45V.

It is an excellent excellent sounding amp (yes I meant to say that twice) but be careful of the SOAR of the output transistors. I have the Motorolla Upgrade - another £80 above the asking price.

Don't bother with the Capacitor Boards as it is far easier to just connect the capacitors banks together with copper bar.

I used 6 x 33000uF per Channel and flattened 8mm Copper tubing.

ByronInLawrence · 27th May 2011, 01:30 PM

Hi Andy,

Thank you for the warning to everyone considering buying from this vendor. I'm glad you got it working and are happy with the results in the end! It looks like a real professional build in the photo.

Please edit your post with a much smaller photo. The photo is so big that only a small part can be seen on an average monitor, and it takes a long time to load.

-Byron

Andy5112405 · 27th May 2011, 01:44 PM

Although the two amplifiers share the same Real Estate, they are completely separate. The only common connection is the Mains Input, after that they are completely separate.

Andy5112405 · 27th May 2011, 01:57 PM

I have never heard of a set-up where the amplifiers are supplied from two different power stations.

poynton · 27th May 2011, 04:08 PM

Quote:

Originally Posted by ByronInLawrence

.......................
Please edit your post with a much smaller photo. The photo is so big that only a small part can be seen on an average monitor, and it takes a long time to load.

-Byron

Agreed !!!

I wish members would post using the inbuilt facility NOT photobucket etc.

I'm still waiting for the huge picture to download while I have written and posted this message.

Andy

.

stoolpigeon · 27th May 2011, 04:19 PM

great idea using copper tube!

sp

Andy5112405 · 27th May 2011, 06:40 PM

Just for the guys with poorer monitors. The initial A700

poynton · 28th May 2011, 01:03 PM

.............. or use the attachment facility and it will remain on the forum for ever - not disappear in a few weeks!

.

Andy5112405 · 10:43 AM

Now that I have finished my Aleph 4 I have no requirement for the EXCELLENT DIY-GENE A700 that preceeded it.

Please note that I have removed the 12 x PSU Electrolytics and the 4 x 25A Bridge Rectifiers. Other than that it is 100% comlete and ready to go.

Supplied with full schematics. This unit is the upgraded version of the A700 with the Motorolla MJ21193 and MJ21194 power transistors.

Fitted with 2 x 500VA 45-0-45V Transformers - both have dual primaries and can be used for 115 or 230V operation.

Item weighs around 30Kg so postage is going to be HIGH.

I'm looking for £100. That's worth it for the transformers alone. The case is in excellent condition and the amplifier modules are both fully functional and tested.

cyclecamper · 18th June 2011, 01:53 PM

Sounds like an exceptional deal for someone local.

So you prefer the sound of the cascode aleph?

27th May 2011, 11:45 AM	#1
Andy5112405 Banned Join Date: Nov 2006 Location: Torpoint	DIY-GENE A700 Mark Levinson Clone Having built one of these "Clones" I have a few words of warning. The design is very robust and the build quality is good. However, the DIY spirit is poor and the supply very poor. My A700 Kit arrived from Hong Kong wrapped in newspaper and sheets of cardboard. The amplifier boards come pre-assembled and tested, they also arrived pre-stressed and most of the transistors bent well away from their natural angle. Several of the power transistor leads had broken away from their PCB lands, however, the PCB had mercifully not been damaged. Several of the taller capacitors had been punctured and two of the small ceramic caps had disappeared (OK the legs were still there) - All down to the appaulling packaging. After a bit of cajoulling, DIY-GENE replaced the faulty components. They were nice enough about the whole polava but after spending many hundreds of pounds on the kit I was anxious to get it going. Don't expect any technical help from these guys, it just aint forthcoming. The kit I received was supplied with SIL-PAD insulators and was biassed at 1.26A. The supplied heatsinks are completely incapable of operating at these levels. After a few days of operation one channel detonated (literally blowing transistor fragments around the amplifier). As a minimum, throw away the SIL-PADs and invest in MICA and GOO. Even this resulted in excessive heatsink temperatures. I eventually had to crank down the bias to 1.0A (ie Class AB operation at high volume) in order to maintain any sort of reliability. OK, I didn't spend the extra cash on purchasing the recommended 42-0-42V transformers, mine are 45-0-45V. It is an excellent excellent sounding amp (yes I meant to say that twice) but be careful of the SOAR of the output transistors. I have the Motorolla Upgrade - another £80 above the asking price. Don't bother with the Capacitor Boards as it is far easier to just connect the capacitors banks together with copper bar. I used 6 x 33000uF per Channel and flattened 8mm Copper tubing.

18th June 2011, 10:39 AM	#9
Andy5112405 Banned Join Date: Nov 2006 Location: Torpoint	FOR SALE - DIY-GENE A700 Now that I have finished my Aleph 4 I have no requirement for the EXCELLENT DIY-GENE A700 that preceeded it. Please note that I have removed the 12 x PSU Electrolytics and the 4 x 25A Bridge Rectifiers. Other than that it is 100% comlete and ready to go. Supplied with full schematics. This unit is the upgraded version of the A700 with the Motorolla MJ21193 and MJ21194 power transistors. Fitted with 2 x 500VA 45-0-45V Transformers - both have dual primaries and can be used for 115 or 230V operation. Item weighs around 30Kg so postage is going to be HIGH. I'm looking for £100. That's worth it for the transformers alone. The case is in excellent condition and the amplifier modules are both fully functional and tested. Last edited by Andy5112405; 18th June 2011 at 10:43 AM.

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27th May 2011, 01:30 PM	#2
ByronInLawrence diyAudio Member Join Date: Nov 2010 Location: Lawrence, a nice little college town in Kansas	Hi Andy, Thank you for the warning to everyone considering buying from this vendor. I'm glad you got it working and are happy with the results in the end! It looks like a real professional build in the photo. Please edit your post with a much smaller photo. The photo is so big that only a small part can be seen on an average monitor, and it takes a long time to load. -Byron

27th May 2011, 01:44 PM	#3
Andy5112405 Banned Join Date: Nov 2006 Location: Torpoint	Although the two amplifiers share the same Real Estate, they are completely separate. The only common connection is the Mains Input, after that they are completely separate.

27th May 2011, 01:57 PM	#4
Andy5112405 Banned Join Date: Nov 2006 Location: Torpoint	I have never heard of a set-up where the amplifiers are supplied from two different power stations.

27th May 2011, 04:19 PM	#6
stoolpigeon diyAudio Member Join Date: Feb 2007 Location: Laputa	great idea using copper tube! sp

27th May 2011, 06:40 PM	#7
Andy5112405 Banned Join Date: Nov 2006 Location: Torpoint	Just for the guys with poorer monitors. The initial A700

18th June 2011, 01:53 PM	#10
cyclecamper diyAudio Member Join Date: May 2010 Location: was Chicago IL, now Long Beach CA	Sounds like an exceptional deal for someone local. So you prefer the sound of the cascode aleph?

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