Rectifier= 5AR4/GZ34. 5AR4 is the North American designation for a GZ34. Many GE and other USA tubes were relabeled Mullards. Current production Russian 5AR4 are decent. Use only a 5AR4 or GZ34 as it has a slow warmup (easier on the rest of the circuit) and only draws 1.9 amps filament current. The 5U4 is a no-no, draws 3 amps.
Full build instructions available at wallofsound.ca.
Full build instructions available at wallofsound.ca.
calpe,
A word or two of advice for beginning builders, please don't take offence.
-Don't over-obsess about the details. You can burn out and lose interest by over-thinking this early in the process.
-You will likely find that 5 or 6 different suppliers will be necessary to get all the bits and pieces you need. It's just a fact of life.
-The SPP is a forgiving design. The flip side is it's not that sensitive to parts selection. But buy decent OPTs, Hammond, Edcor, Primary Windings, whatever, though.
-I think you said you already have the SPP board?
-Next order trannies and a chassis. Then some tubes and sockets.
-Once you have these and can visualize the finished amp, then bits and pieces like switches, volume pot (if desired), jacks, speaker connectors will make sense.
-Lastly, order all the small parts, resistors, capacitors, spacers, nuts, bolts etc.
-With all of the parts to hand, do a dry run placing all the bits and pieces on/in your chassis. It should all make sense then and if it doesn't, we're here to help.
Cheers, S.
A word or two of advice for beginning builders, please don't take offence.
-Don't over-obsess about the details. You can burn out and lose interest by over-thinking this early in the process.
-You will likely find that 5 or 6 different suppliers will be necessary to get all the bits and pieces you need. It's just a fact of life.
-The SPP is a forgiving design. The flip side is it's not that sensitive to parts selection. But buy decent OPTs, Hammond, Edcor, Primary Windings, whatever, though.
-I think you said you already have the SPP board?
-Next order trannies and a chassis. Then some tubes and sockets.
-Once you have these and can visualize the finished amp, then bits and pieces like switches, volume pot (if desired), jacks, speaker connectors will make sense.
-Lastly, order all the small parts, resistors, capacitors, spacers, nuts, bolts etc.
-With all of the parts to hand, do a dry run placing all the bits and pieces on/in your chassis. It should all make sense then and if it doesn't, we're here to help.
Cheers, S.
No offence taken Steve. Agreed i am too precautious, i apologise to the readers.
I don't wish to burn out anyone's valuable thoughts and ideas.
But having built two articles from articles in the Elektor magazine, has made me that way. Both had lots of unknown, unexpected issues, Elektor design errors, i had to solve, and it was just a nightmare! Result though was incredible!
https://www.elektormagazine.com/magazine/elektor-201309/23330
https://www.diyaudio.com/community/threads/my-q-watt-project.301100/
I then built the Elektor Pre-Amplifier https://www.elektormagazine.com/magazine/elektor-201204/19844
https://www.diyaudio.com/community/threads/elektors-preamplifier-2012-in-2017.305112/
I hope to receive the SPP PCB soon.
Sadly, where i live, suppliers charge very high shipping costs, then i have import duty on top. So i'll have to opt to ship to my In-Laws in the neighbouring Spanish town, as costs will be a lot lower.
I try to read replies, check items i need, but my time is quite limited and this frustrates me.
Having read George's reply (Tubelab) explaining his web site was hacked must be the reason why some text is explained twice, the second time must be incorrect. Perhaps George can rectify the SPP write up, Parts List etc., not only for his self satisfaction but also for all his readers/builders?
I hope to order the Mains Transformer and Audio o/p transformer today....
Thank you to everyone
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The 5AR4 / GZ34 is the recommended rectifier tube. That said, there will always be people who will "roll in" other tubes including the 5U4. The 5U4 will work in the SPP ONLY if you have a 3 amp 5 volt winding. Other 2 amp tubes like the 5Y3 will have a short unhappy life in the SPP.
The wall of sound build instructions are good. My only issue with it is the drilling of holes in the PC board for template use. Print the enclosed file, verify that it is the proper size and scale if needed as some printers are not exactly 1:1. You can tape the printed image to your chassis and drill or center punch right through the paper eliminating several possible errors.
My wife is the other half of Tubelab the corporation. She has desired the closing down of the company for a few years now, as it takes lots of time and produces no income. I have managed to keep Tubelab alive, but this year's economy is a challenge. With near zero sales I will not likely spend a lot of time redoing my web site.
Thank you George for your response, and i'm 100% sure everyone appreciates your very valuable assistance in all matters.
Yes, it has been a couple of tough years with the various world issues effecting us all.
So may i request that you continue (and your wife) giving pleasure to us all on your great experience giving us all joy and pleasure.
Thank you George and Sherri Anderson (Tubelab).
Yes, it has been a couple of tough years with the various world issues effecting us all.
So may i request that you continue (and your wife) giving pleasure to us all on your great experience giving us all joy and pleasure.
Thank you George and Sherri Anderson (Tubelab).
I think you are one of the few to have shared so much and contributed so much to this small world of diy dedicated to audio, thank you 1000 times.
I faced the same problem as you when I started my repair business, lots of people talking, few people paying.
The paradox is that if I had fixed 10 car keys a day, today I would be rich. I went back to paid work and I am earning money again, end of story.
Thank you again for everything you taught me and everything I understood by reading you.
I've finally began checking through the parts list.
I'm assuming Tubelab didn't come across an issue of 'lite' and 'heavy' transformers, and then having to alter resistor values?
In the Wall of Sound https://wallofsound.ca/audioreviews...nsformers-integration-and-wiring/#prettyPhoto it talks of 'lite' and 'heavy' transformers.
They say that the Hammond 272HX (USA) is a 'Lite' version. 600V, 6.3V, 5V - 230mA, 6A, 3A
The Hammond 272JX (USA) is a 'Heavy' version, 600V, 6.3V, 5V - 287mA, 8A, 4A
Assuming the 272JX being classed as 'heavy' having higher current outputs.
I therefore assume that the https://primarywindings.com/product/mains-transformer-mullard-5-10-stereo/ would be classed as a 'lite' transformer?
600V @200mA CT, 6.3V @4A and 6.3V/5V @ 2A
If my Mains Transformer is 'lite' then i should be fine with Tubelab's resistor values and that the valves will work in their comfort zone?
How does someone decide on what valve manufacturer to chose?
1x 5AR4
2x 12AT7
4x EL84
Thanks
I'm assuming Tubelab didn't come across an issue of 'lite' and 'heavy' transformers, and then having to alter resistor values?
In the Wall of Sound https://wallofsound.ca/audioreviews...nsformers-integration-and-wiring/#prettyPhoto it talks of 'lite' and 'heavy' transformers.
They say that the Hammond 272HX (USA) is a 'Lite' version. 600V, 6.3V, 5V - 230mA, 6A, 3A
The Hammond 272JX (USA) is a 'Heavy' version, 600V, 6.3V, 5V - 287mA, 8A, 4A
Assuming the 272JX being classed as 'heavy' having higher current outputs.
I therefore assume that the https://primarywindings.com/product/mains-transformer-mullard-5-10-stereo/ would be classed as a 'lite' transformer?
600V @200mA CT, 6.3V @4A and 6.3V/5V @ 2A
If my Mains Transformer is 'lite' then i should be fine with Tubelab's resistor values and that the valves will work in their comfort zone?
How does someone decide on what valve manufacturer to chose?
1x 5AR4
2x 12AT7
4x EL84
Thanks
Thank you Stephe for that valuable information.
Question is do i try and source the Valves from a European/USA source or perhaps have a look at AliExpress web site?
calpe,
Here's one tube and socket supplier in Europe: https://www.tube-town.net/ttstore/tubes/
Look at one of the other SPP build threads, I gave a link earlier in this thread, PM the builders that live in Europe and ask them where they bought theirs tubes.
There were two reasons for the light and heavy:
1. Hammond power transformers are known to run hot, so a "heavy" will run less hot.
2. A "heavy" (bigger, weighs more) output transformer should have better low-end response.
In Canada (home of Hammond) the price difference between the "lite and heavy" isn't that much.
Here's one tube and socket supplier in Europe: https://www.tube-town.net/ttstore/tubes/
Look at one of the other SPP build threads, I gave a link earlier in this thread, PM the builders that live in Europe and ask them where they bought theirs tubes.
There were two reasons for the light and heavy:
1. Hammond power transformers are known to run hot, so a "heavy" will run less hot.
2. A "heavy" (bigger, weighs more) output transformer should have better low-end response.
In Canada (home of Hammond) the price difference between the "lite and heavy" isn't that much.
huggygood, might be worthwhile if you started a separate thread on that subject, your sure to get good responses from those that are familiar with it
Some further advise on the tubes please.
Stephe https://m.youtube.com/c/SkunkieDesignsElectronics kindly said to avoid the JJ 5AR4's
It appears clear to try and avoid Chinese productions.
So do the 12AT7's and EL84's have to be a matched pairs?
I've been looking at https://www.watfordvalves.com/ and also https://www.hificollective.co.uk/valvehome1.html
Stephe https://m.youtube.com/c/SkunkieDesignsElectronics kindly said to avoid the JJ 5AR4's
It appears clear to try and avoid Chinese productions.
So do the 12AT7's and EL84's have to be a matched pairs?
I've been looking at https://www.watfordvalves.com/ and also https://www.hificollective.co.uk/valvehome1.html
Some advise please, as I've been looking at these, but to check with the readers as to what should be chosen : -
https://watfordvalves.com
EL84's
EL84-ELECTRO HARMONIX Electro Harmonix
EL84-HARMA RETRO
EL84-SOVTEK
12AT7 (ECC81's?)
ECC81-HARMA STR
ECC81-SIEMENS EG
ECC81/12AT7-GENERAL ELECTRIC
5AR4
GZ34/5AR4-GROOVE TUBES SUPER PREMIUM
GZ34/5AR4-SOVTEK
I've also seen similar tubes types in AliExpress by PSVANE
https://watfordvalves.com
EL84's
EL84-ELECTRO HARMONIX Electro Harmonix
EL84-HARMA RETRO
EL84-SOVTEK
12AT7 (ECC81's?)
ECC81-HARMA STR
ECC81-SIEMENS EG
ECC81/12AT7-GENERAL ELECTRIC
5AR4
GZ34/5AR4-GROOVE TUBES SUPER PREMIUM
GZ34/5AR4-SOVTEK
I've also seen similar tubes types in AliExpress by PSVANE
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If you can get the SOVTEK EL84M, go for it, it seems to be a modern build of the 6P14P-EV, which is famous for durability and quality.