I wish these red resistors were available here.
Shaan, this is the manufacturers link:
Precision Resistive Products | Precision Resistive Products, Inc.
I think HifiCollective carries them.
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No, I have already a V4 (50W) running nicely in dual mono with toroidal transformer and 40000uF / channel.
I wanted to upgrade to the V4H and build the second one for my cousin.
This time I decided to try SMPS, so it will be dual Crestnest 600W
Other difference will be the Exicon this time (selected version, so I'm thinking of putting wire instead of 0.1R).
I wanted to upgrade to the V4H and build the second one for my cousin.
This time I decided to try SMPS, so it will be dual Crestnest 600W
Other difference will be the Exicon this time (selected version, so I'm thinking of putting wire instead of 0.1R).
Sounds like we have similar plans, looking forward to sharing experiences.
I believe Sami has the SMPS600’s on special until the end of December if you don’t have them already.
I made some more progress, one channel successfully powered up!
Shaan, your assembly manual is fantastic!! Step by step is clearly written and very easy to follow. VAS and MosFet biasing procedure went extremely smooth. Final bias is rock solid at 217mV and offset varies between -1.5 to 2.0mV. I would have had both channels fired up but I’m short two capacitors
Didn’t connect speakers or input yet, that’s next time
Shaan, your assembly manual is fantastic!! Step by step is clearly written and very easy to follow. VAS and MosFet biasing procedure went extremely smooth. Final bias is rock solid at 217mV and offset varies between -1.5 to 2.0mV. I would have had both channels fired up but I’m short two capacitors
Didn’t connect speakers or input yet, that’s next time
Attachments
I’ll be doing a boring old linear PSU using dual mono Prasi’s CRC and 300va 40v Anteks.
Vunce, the heatsink looks great, glad you had a successful setup and wishing you the same success with the second channel. Did you mill the block between the heatsink and board yourself?
For my own build I have been waffling on the actual chassis construction. The original plan was to use some extra beefy heatsinks I found on eBay and building a chassis around them. I hit a creative block and couldn’t come up with a design I loved.
Last week on eBay, I found a glorious heatsink laden auction that I couldn’t pass up: Wheatstone Audioarts PSC-1000 Power Supply for Broadcast Radio Console | eBay. This beautiful, 74 lbs, 5U donor is a 1600w regulated linear supply for a 90s era TV mixing console. Some pics of it’s meticulous wiring and construction are attached, I hope it’s new life as a V4H will do it justice.
I just disassembled and started cleaning everything - so much thermal compound to clean off. Next, I have a bit of metal work to do, new faceplate, new angle brackets to mount the v4h boards and figuring out the bottom mounting situation. Hopefully this is one build that I won’t regret having too small - or just small enough - of a chassis, there should be plenty of room.
Greg
Vunce, the heatsink looks great, glad you had a successful setup and wishing you the same success with the second channel. Did you mill the block between the heatsink and board yourself?
For my own build I have been waffling on the actual chassis construction. The original plan was to use some extra beefy heatsinks I found on eBay and building a chassis around them. I hit a creative block and couldn’t come up with a design I loved.
Last week on eBay, I found a glorious heatsink laden auction that I couldn’t pass up: Wheatstone Audioarts PSC-1000 Power Supply for Broadcast Radio Console | eBay. This beautiful, 74 lbs, 5U donor is a 1600w regulated linear supply for a 90s era TV mixing console. Some pics of it’s meticulous wiring and construction are attached, I hope it’s new life as a V4H will do it justice.
I just disassembled and started cleaning everything - so much thermal compound to clean off. Next, I have a bit of metal work to do, new faceplate, new angle brackets to mount the v4h boards and figuring out the bottom mounting situation. Hopefully this is one build that I won’t regret having too small - or just small enough - of a chassis, there should be plenty of room.
Greg
Attachments
Holy Mackerel Greg, that chassis is giant!!
From my short time with the V4H fired up, you will have nooooo problem keeping it cool. It doesn’t run that hot, after 1 hour the heatsinks are 41°C. Yes, I machined the blocks(drill press, filing and elbow grease)
Both channels are tuned up and working beautiful....but separately!! As soon as I hook up both channels to my pre I get hum and buzz
Individually powered they are totally silent, can’t even tell it’s on. I’ve got some details to work out........
From my short time with the V4H fired up, you will have nooooo problem keeping it cool. It doesn’t run that hot, after 1 hour the heatsinks are 41°C. Yes, I machined the blocks(drill press, filing and elbow grease
)Both channels are tuned up and working beautiful....but separately!! As soon as I hook up both channels to my pre I get hum and buzz
Individually powered they are totally silent, can’t even tell it’s on. I’ve got some details to work out........
Attachments
Holy Mackerel Greg, that chassis is giant!!
From my short time with the V4H fired up, you will have nooooo problem keeping it cool. It doesn’t run that hot, after 1 hour the heatsinks are 41°C. Yes, I machined the blocks(drill press, filing and elbow grease
Both channels are tuned up and working beautiful....but separately!! As soon as I hook up both channels to my pre I get hum and buzz
Individually powered they are totally silent, can’t even tell it’s on. I’ve got some details to work out........
Nice work !
1200W psu is big !!
I'm looking forward to hear your impressions about the sound when you fix the hum problem !
Fabio
Thanks Fabio,
Probably a bit of overkill, but I had it for another project that never happened.
The V4H has been in use all day driving 4ohm bookshelf speakers and really sounds wonderful.
Cheers,
Vunce
Details addressed=very quiet amplifier!
So, by placing the ground loop breaker between the psu 0V and SGND on the V4H board I have an almost silent amplifier!! The hum and hiss is inaudible with the current set of bookshelf speakers connected. I say “almost” because my main speakers are very efficient at 99dB and pick up the slightest noise.
Christmas came early for me
So, by placing the ground loop breaker between the psu 0V and SGND on the V4H board I have an almost silent amplifier!! The hum and hiss is inaudible with the current set of bookshelf speakers connected. I say “almost” because my main speakers are very efficient at 99dB and pick up the slightest noise.
Christmas came early for me
So, by placing the ground loop breaker between the psu 0V and SGND on the V4H board I have an almost silent amplifier!! The hum and hiss is inaudible with the current set of bookshelf speakers connected. I say “almost” because my main speakers are very efficient at 99dB and pick up the slightest noise.
Christmas came early for me
Hi Vunce.
Great news. You may also want to keep the input wires far from mains, rails and speaker wires and twist every pair of wires. This helped me lower the noise in my system significantly.
