2023 Audio Plans
- Thread starter asilker
- Start date
You can’t just leave it like that
There's a hint on the box.You can’t just leave it like that
It's unpacked and working well now though. Pics of the rack aren't good due to backlighting so this will help:
Enjoying it with stock JJ's right now, this is a good sign.
Oh wow!
First off, I want to say thank you for responding to the question about what’s in the box. I was dreading someone responding back with an SNL skit GIF.
Second off, that thing looks downright sexy! Probably, the nicest looking phono stage I’ve ever seen to date. If it performs half as good as it looks, then it’s money well spent!
You're welcome. I had my fun with the box, no need to drag it out. It seems really well made, this is the original version they started the company with. There's a blemish on the front that I can't see from my listening chair, other than that it's really clean. The former owner was moving up the line.
I've found that with each improvement I've made on the analogue side I spin more records, looks like this trend is continuing. Pretty happy with it so far.
How about I finish at least FIVE of the currently unfinished projects ???.
1. A BIG 807 based ( eight of them ) power amp. Hand made, and designed ( by me ) BIG output transformers that weigh 6 kilos each.
2. Power supply for above. Dual mono all the way through, EXCEPT the power switch and relays. LARGE custom toroids for power.
3. Finish restoring a 1962 kit project, that now has separate regulated PSU.
4. Finish designing my valve tester. I have all the parts ( I think
).
5. Start cutting, bending and drilling aluminium for above valve tester.
Pic 1. Power amp. about 50 watts RMS ( NOT peak ) per channel. All pure class A. ( will NEVER be used at that level )
4 off 5B/254 which are modern 807's in a loctal base. NOS English made for the military. I have a couple of buckets of them.
For a few other topics posted: 807 and derivatives one of the finest BIG tetrodes made. ( my opinion )
Pic 2. Vintage pre: A 1962 Australian pre amp kit, based on the origional Mullard design. 4 off EF86 . Modified to use VERY low noise Military version of 6BR7, CV 4006.
Pic 3. Vintage pre PSU top view. Transformer from Akai reel to reel tape deck. Valve rectifier Aircraft grade CV 5009, AKA 6X4.
2 off neon regulators in series, one OB2, and one OA2. DC heaters to be added.
Under is under chassis view of same. PLenty of room for bridge and regulator for heaters. CSIRO designed 15 Henry 70 mA choke supply. So CLC filtered and neon regulated HT. Case is some junk I bought at disposal store and cut the bottom off, added perforated steel base plate and rubber feet.
Joe
1. A BIG 807 based ( eight of them ) power amp. Hand made, and designed ( by me ) BIG output transformers that weigh 6 kilos each.
2. Power supply for above. Dual mono all the way through, EXCEPT the power switch and relays. LARGE custom toroids for power.
3. Finish restoring a 1962 kit project, that now has separate regulated PSU.
4. Finish designing my valve tester. I have all the parts ( I think
).5. Start cutting, bending and drilling aluminium for above valve tester.
Pic 1. Power amp. about 50 watts RMS ( NOT peak ) per channel. All pure class A. ( will NEVER be used at that level )
4 off 5B/254 which are modern 807's in a loctal base. NOS English made for the military. I have a couple of buckets of them.
For a few other topics posted: 807 and derivatives one of the finest BIG tetrodes made. ( my opinion )
Pic 2. Vintage pre: A 1962 Australian pre amp kit, based on the origional Mullard design. 4 off EF86 . Modified to use VERY low noise Military version of 6BR7, CV 4006.
Pic 3. Vintage pre PSU top view. Transformer from Akai reel to reel tape deck. Valve rectifier Aircraft grade CV 5009, AKA 6X4.
2 off neon regulators in series, one OB2, and one OA2. DC heaters to be added.
Under is under chassis view of same. PLenty of room for bridge and regulator for heaters. CSIRO designed 15 Henry 70 mA choke supply. So CLC filtered and neon regulated HT. Case is some junk I bought at disposal store and cut the bottom off, added perforated steel base plate and rubber feet.
Joe
Attachments
This looks like a reasonable list.How about I finish at least FIVE of the currently unfinished projects ???.
1. A BIG 807 based ( eight of them ) power amp. Hand made, and designed ( by me ) BIG output transformers that weigh 6 kilos each.
2. Power supply for above. Dual mono all the way through, EXCEPT the power switch and relays. LARGE custom toroids for power.
3. Finish restoring a 1962 kit project, that now has separate regulated PSU.
4. Finish designing my valve tester. I have all the parts ( I think
5. Start cutting, bending and drilling aluminium for above valve tester.
Pic 1. Power amp. about 50 watts RMS ( NOT peak ) per channel. All pure class A. ( will NEVER be used at that level )
4 off 5B/254 which are modern 807's in a loctal base. NOS English made for the military. I have a couple of buckets of them.
For a few other topics posted: 807 and derivatives one of the finest BIG tetrodes made. ( my opinion )
Pic 2. Vintage pre: A 1962 Australian pre amp kit, based on the origional Mullard design. 4 off EF86 . Modified to use VERY low noise Military version of 6BR7, CV 4006.
Pic 3. Vintage pre PSU top view. Transformer from Akai reel to reel tape deck. Valve rectifier Aircraft grade CV 5009, AKA 6X4.
2 off neon regulators in series, one OB2, and one OA2. DC heaters to be added.
Under is under chassis view of same. PLenty of room for bridge and regulator for heaters. CSIRO designed 15 Henry 70 mA choke supply. So CLC filtered and neon regulated HT. Case is some junk I bought at disposal store and cut the bottom off, added perforated steel base plate and rubber feet.
Joe
Very tidy builds and welcome to the haven!
I still have to finish the amp build, then I will finish lacing the wiring looms. I cant do that untill I have finished initial setup and testing.
I "stole " the amp design. Its by Joseph Marshall, a very prominant American designer from the mid 1950,s.
He was a master engineer that really knew what he was doing. The design is from Audio Magazine Aug 1956, so its still younger than I am
It was called " The Laboratory Goldenears Amplifier". It used selected KT66 valves, but as they fetch schtoopid amounts of money today, I used 5B/254 AKA CV428, which I mentioned I have plenty of. They are almost exactly the same as KT66, or 6L6 or 807, all of which belong to the wellknown bunch of output bottles developed by RCA ( origionally ) but many try and claim the honour for other brands.
Output transformers are my own 9 section, ultra linear design using five staggered primary sections and four parallel secondaries, suplying 8 ohms only. Multi impedance output transformers are never perfect for any particular impedance, regardless of what the stamped numbers say. Read any of Hafler and Keroes many engineering briefs and patents that they provided. They are wound on 5% silicon, grain oriented Australian made iron last made in the late 80's, before that section of BHP ( John Sankey ) was sold off. They are the same size as a 400 watt mains transformer ( even at 50 Hz ). I designed them to be essentially flat from 30 Hz to 50 kilohertz without any feedback or tweaking. With feedback I am hoping for something well over 100 Khz dead flat.
Final results will rely on my build
So I hope I can achieve something similar to Marshalls results. Bottom end rolloff is 4 Hz !!. topend is over the top. The whole design is almost exactly what you find in an oscilloscope vertical amplifer when its AC coupled.
There are only two capacitors in each channel that have anything to do with the signal path. They couple the cathode follower drivers to the output valves.
Heres hoping.
Joe
I "stole " the amp design. Its by Joseph Marshall, a very prominant American designer from the mid 1950,s.
He was a master engineer that really knew what he was doing. The design is from Audio Magazine Aug 1956, so its still younger than I am
It was called " The Laboratory Goldenears Amplifier". It used selected KT66 valves, but as they fetch schtoopid amounts of money today, I used 5B/254 AKA CV428, which I mentioned I have plenty of. They are almost exactly the same as KT66, or 6L6 or 807, all of which belong to the wellknown bunch of output bottles developed by RCA ( origionally ) but many try and claim the honour for other brands.
Output transformers are my own 9 section, ultra linear design using five staggered primary sections and four parallel secondaries, suplying 8 ohms only. Multi impedance output transformers are never perfect for any particular impedance, regardless of what the stamped numbers say. Read any of Hafler and Keroes many engineering briefs and patents that they provided. They are wound on 5% silicon, grain oriented Australian made iron last made in the late 80's, before that section of BHP ( John Sankey ) was sold off. They are the same size as a 400 watt mains transformer ( even at 50 Hz ). I designed them to be essentially flat from 30 Hz to 50 kilohertz without any feedback or tweaking. With feedback I am hoping for something well over 100 Khz dead flat.
Final results will rely on my build
So I hope I can achieve something similar to Marshalls results. Bottom end rolloff is 4 Hz !!. topend is over the top. The whole design is almost exactly what you find in an oscilloscope vertical amplifer when its AC coupled.There are only two capacitors in each channel that have anything to do with the signal path. They couple the cathode follower drivers to the output valves.
Heres hoping.
Joe
If forum gifs are causing you dread, I would be happy to refer you to a good therapist
Nooo, not the Bisons!
After some recent listening I’m in no rush to change them out; probably not for a few years yet. They are designed to suit my room and system and are such nice sounding speakers, but big and heavy at circa 100kg each.
I wasn't thinking about this at the time you posted @Wardsweb , but had you done any tube rolling with the Zesto ?
Not with the Zesto but in other gear and tubes do make a difference. Be it synergy with other pieces in the system or personal preference. There is something behind the love of old Telefunkin, Mullard, RCA, GE, etc...
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