You still have the huge cap bank on board the amp PCB. For all intents and purposes, that is your important low ESR cap. The caps on the PSU board are simply for smoothing the AC ripple - which is not needed when you have a SMPS and a cap multiplier.
There is more storage on the amp PCB now with newly spec'd 560uf caps. But you'll still hit a wall where some tone will be lost if you don't have very efficient speakers. You simply cannot fill the amp caps up fast enough if you have a sizeable demand of current to the speakers.
You've got an SMPS on one side as a infinite reservoir, then you've got a high quality 6720uf reservoir on the other side. The issue is you've got a small reservoir between them that won't provide the current needed. The ripple current of a 1500uf cap is less than 2A (the cap multiplier might hit a full 2A), where as you need ~4A for the amp's full ability.
Trust me, I've used both a infinite and limited cap multiplier. The infinite sounds better. In fact using a limited one was first. The improvements were clear, but it got a lot better when advancing into the infinite!
What I could do if there was some huge demand for less power is calculate some new values for the KMR section to lower the voltage regulation.
You've got an SMPS on one side as a infinite reservoir, then you've got a high quality 6720uf reservoir on the other side. The issue is you've got a small reservoir between them that won't provide the current needed. The ripple current of a 1500uf cap is less than 2A (the cap multiplier might hit a full 2A), where as you need ~4A for the amp's full ability.
Trust me, I've used both a infinite and limited cap multiplier. The infinite sounds better. In fact using a limited one was first. The improvements were clear, but it got a lot better when advancing into the infinite!
What I could do if there was some huge demand for less power is calculate some new values for the KMR section to lower the voltage regulation.
Hi Jeremy,
My boards have arrived in Amsterdam already - much faster than I had expected.
I will start collecting the parts and hope to be building soon.
Take care,
Laurens
My boards have arrived in Amsterdam already - much faster than I had expected.
I will start collecting the parts and hope to be building soon.
Take care,
Laurens
I got mine today, allthough it might have arrived some days ago, my mailbox is not checked for content every day. The boards are really nice.
If you didn't get my email with all the information including BOM, PM/email me your email address. folsom.jeremyh@gmail.com
There is a shortage of the D45 I spec'd at Mouser. I am sure it can be found on Digikey or Newark or something. But there's a few 863-D45VH10G at Mouser that'll work for now.
Thanks Jeremy!
When you say will work for now does that mean it's not a permanent replacement ?
Will it need more heat sink because of the higher power dissipation ?
When you say will work for now does that mean it's not a permanent replacement ?
Will it need more heat sink because of the higher power dissipation ?
I just mean till the other is back in stock, as a recommended part. I can leave the one in the BOM as it will become avaliable again and is other places.
I have 2 amp boards. If I build them in the same chassis making a 4 channel amp do I just double the size of the transformer or use two transformers?
The 175va Hammond transformer will work, but you could also use a 250va toroid.
You could go with 10kuf caps to use one Antipole. But I think general consenus is you get some improvements by keeping things seperate. Many may say two transformers is better, but its a question of budget and space too.
So if you use two Antipoles, you could use the 185G36 Hammond, and run an Antipole of off each output since it has dual secondaries. The same goes for a Toroid with dual secondaries as opposed to a center tap unit where you would skip the center tap and run both Antipoles on the same output that is across the whole transformer (at the right voltage).
You could go with 10kuf caps to use one Antipole. But I think general consenus is you get some improvements by keeping things seperate. Many may say two transformers is better, but its a question of budget and space too.
So if you use two Antipoles, you could use the 185G36 Hammond, and run an Antipole of off each output since it has dual secondaries. The same goes for a Toroid with dual secondaries as opposed to a center tap unit where you would skip the center tap and run both Antipoles on the same output that is across the whole transformer (at the right voltage).
I was going to use two antipoles. Antek has a 200 and a 300 VA transformers, no 250. So should I get the 300 or would a 200 be enough? 15V or 18V?
200va is enough. Use 18v
I would probably go with 300va, persoanlly, but it will work with 200va. I prefer "overkill" for PSU, it ensures good tone.
I would probably go with 300va, persoanlly, but it will work with 200va. I prefer "overkill" for PSU, it ensures good tone.
i received the boards and everything is fine. just need a bit help.
is the 863-D45VH10G instead of D45 definitive and good quality or in the future i have to buy the d45 in future?
another thing about the transformer:
i´m in europe so i need a 220v primary.
is it ok to buy with this specs??
220 volts primary 16v secondary and 130va 8.1 amps?
should i buy el or toroid type or other??
thank you very much
is the 863-D45VH10G instead of D45 definitive and good quality or in the future i have to buy the d45 in future?
another thing about the transformer:
i´m in europe so i need a 220v primary.
is it ok to buy with this specs??
220 volts primary 16v secondary and 130va 8.1 amps?
should i buy el or toroid type or other??
thank you very much
Whatever one is in the BOM is good, for D45s.
The transformer in BOM will work on euro voltages when wired for them. But you can always use a 16-18v toroid if you wish.
I prefer the dual bobbin because they block more RF, but you have to isolate them a little because they hum more.
The transformer in BOM will work on euro voltages when wired for them. But you can always use a 16-18v toroid if you wish.
I prefer the dual bobbin because they block more RF, but you have to isolate them a little because they hum more.
the boom has D45H11G but is out of stock on mouser etc...
is there a better part for the replace of D45H11G Bipolar Transistors - BJT 10A 80V 50W PNP ?