Good thinking and I use a similar but different idea. I put the output section in one box and the input section in another box, each with their own PSU. This allows me to use a 5U4G rectifier for the output and a AZ1 mesh for the input section. I just love my AZ1 mesh tubes!
In response to the weight issue, I really don't want to be lifting much over 12kg in a single chassis and less is good. So I routinely use 2 chassis, sometimes up to 4 chassis if I'm making OTT filament supplies with choke input.
I absolutely do NOT want to be constantly moving anything over 15kg about from bench to listening rack. This is not negotiable and the suggestions of using lifting gear or trolleys is just not going to happen. A lot of commercial amps are far too heavy and even require 2 people. For DIY you are constantly moving your amps around, turning them over and sidewise etc.
The suggestion of screwing top plates to an aluminium frame is exactly what I've done for 10 years, using 2U computer parts - horizontal rails with threaded inserts. Very flexible system.
You guys have helped me resist the idea of an ABS rack size case for all the good reasons given. Thank you!! I do use ABS cases for filament supplies though - convenient and easy to work with and low heat, low voltage.
The weight issue deserves much more discussion and is a whole other question. By all means continue to discuss it. ABS and aluminium aren't too different as already stated. The big issue is dividing the chassis in 2 (or more) for comfortable lifting and working. Or simply being aware of the issue for those who can't or don't want to lift heavy gear when working on it.
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You could get rid of a few kilograms by using SMPS instead of linear. SS rectification instead of tubes. It all depends on the power output I guess...
Also, if you build it right, you won't need to keep moving it from the rack to the bench, right? 🙂
12kg is doable though.
This amp weighs about 7kg and uses SMPS for heaters, linear for B+. Output 10W triode.
Also, if you build it right, you won't need to keep moving it from the rack to the bench, right? 🙂
12kg is doable though.
This amp weighs about 7kg and uses SMPS for heaters, linear for B+. Output 10W triode.
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I am the friend Andy is refering to I think. Im 82,quite fit but I have a hernia problem.
I have a problem with lifting weighty items at the moment. Its not just getting them up the stairs to my listening room/workshop its lifting them in and out of the rack onto the workbench and turning them over if necessary. Its the transformers which are the main
problem.
Im an EE by profession, I like the sound of valve equipment best so Im attempting to resolve the problem by using smps quite succesfully so far.
Being called for supper now !
I am an electronic engineer by profession and have built all my equipment for many
years both solid state and valves which I prefer
and understand all the safety issues with smps which Im wor electronic engine
I have a problem with lifting weighty items at the moment. Its not just getting them up the stairs to my listening room/workshop its lifting them in and out of the rack onto the workbench and turning them over if necessary. Its the transformers which are the main
problem.
Im an EE by profession, I like the sound of valve equipment best so Im attempting to resolve the problem by using smps quite succesfully so far.
Being called for supper now !
I am an electronic engineer by profession and have built all my equipment for many
years both solid state and valves which I prefer
and understand all the safety issues with smps which Im wor electronic engine
Ah - you've entered the conversation Zeta4! Yes, we've been emailing each other about the weight of the equipment and how to distribute it. I've also been turned on to SMPS supplies like kodabmx says. New for me. For sure I'm going to be much more weight conscious in future. I move my amps around constantly to try different tweaks to the design.
I've gone from 300b to 2a3 for the last build with AC heating and smaller OPTs. That has all helped. OPTs are less than 1.5kg each - don't need more for a 2a3. I used to be insensitive to weight but after building amps for 10 years I'm 10 years older! In my youth I used to sling 50kg bags of cement about but no more...... in fact nothing like it.
I've gone from 300b to 2a3 for the last build with AC heating and smaller OPTs. That has all helped. OPTs are less than 1.5kg each - don't need more for a 2a3. I used to be insensitive to weight but after building amps for 10 years I'm 10 years older! In my youth I used to sling 50kg bags of cement about but no more...... in fact nothing like it.
We all think we are invincible but eventually, stuff happens. In my case, a triple bypass and a subsequent statin-induced disease where antibodies in my bloodstream attack my muscles. Fortunately, I have mostly recovered but I still try to use weight-reducing techniques where possible. These include
1 - lightweight materials - drill holes in places where it's electrically possible and of course, they are good for ventilation
2 - think about whether you can replace chokes with semi-conductors such as the FQPF8N60C that Petr Millett used in his engineer amp
Posted new P-P power amp design
3 - build modular so that you can keep heavy output transformers external to the main circuitry and connected by plugs and jacks. Obviously, you need to make it difficult for prying fingers to access these connectors
4 - investigate SMPS units instead of linear supplies
5 - for DHT, investigate high frequency AC supplies such as those used here
RH Amplifiers: RH813 – The Flagship Project
Another issue is soldering. I had trouble holding the iron steady and had to position my hand against something solid to reduce the tremor. I now use 5 barrel Wago connectors for my star ground.
WAGO 221 | WAGO AU
Sometime, I will try to build an amp with the minimum solder connections possible.
And of course, higher-powered reader glasses so you can see what you are doing as well as brighter lighting.
If you are on statins, you should be aware of this disease.
Statin-associated autoimmune myopathy - Wikipedia
ray
1 - lightweight materials - drill holes in places where it's electrically possible and of course, they are good for ventilation
2 - think about whether you can replace chokes with semi-conductors such as the FQPF8N60C that Petr Millett used in his engineer amp
Posted new P-P power amp design
3 - build modular so that you can keep heavy output transformers external to the main circuitry and connected by plugs and jacks. Obviously, you need to make it difficult for prying fingers to access these connectors
4 - investigate SMPS units instead of linear supplies
5 - for DHT, investigate high frequency AC supplies such as those used here
RH Amplifiers: RH813 – The Flagship Project
Another issue is soldering. I had trouble holding the iron steady and had to position my hand against something solid to reduce the tremor. I now use 5 barrel Wago connectors for my star ground.
WAGO 221 | WAGO AU
Sometime, I will try to build an amp with the minimum solder connections possible.
And of course, higher-powered reader glasses so you can see what you are doing as well as brighter lighting.
If you are on statins, you should be aware of this disease.
Statin-associated autoimmune myopathy - Wikipedia
ray
On the subject of SMPS.
I use these for heaters. AC DC Converter LED Driver 110V 220V to DC 12V 13A 150W Switching Power Supply Board Power Source Module|Switching Power Supply| - AliExpress
I wire pairs of 6V tubes in series and connect them all in parallel to run from 12V.
So far, these have run for almost a year 24/7 in a 65-70°C chassis (unventilated) without modification (better caps?).
This might not seem like much of an accomplishment compared to the life of the AC passive supply, but it's pretty nice for the price point. I have used probably 5 of them and never had a failure.
They start into cold tubes, too - no hiccups like I've complained of with other supplies... 4x6P45S, 2x6SN7, 2x6F12P == ~6 amperes @ 12V when hot - much more when cold.
I use these for heaters. AC DC Converter LED Driver 110V 220V to DC 12V 13A 150W Switching Power Supply Board Power Source Module|Switching Power Supply| - AliExpress
I wire pairs of 6V tubes in series and connect them all in parallel to run from 12V.
So far, these have run for almost a year 24/7 in a 65-70°C chassis (unventilated) without modification (better caps?).
This might not seem like much of an accomplishment compared to the life of the AC passive supply, but it's pretty nice for the price point. I have used probably 5 of them and never had a failure.
They start into cold tubes, too - no hiccups like I've complained of with other supplies... 4x6P45S, 2x6SN7, 2x6F12P == ~6 amperes @ 12V when hot - much more when cold.
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