Nico Ras - There's nothing to establish really... All metal MOSFETS and transistors in general ALWAYS sound better than their plastic counterparts. Regardless of manufacturer, or model. In my personal experience, I've never once heard a plastic transistor sound better than metal can. While I don't know the exact reason behind this, I suspect it's due to metal transistors higher manufacturing quality because of military spec.
1000 posts
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By the way everyone, this thread has passed 100,000 views!!!!
Also has passed 1000 posts in so few days!
Hi Thanh1973,
The snapping idea would be the same as dangling wire which had been discussed a couple of post in this thread before. Try to read them.
Krisfr
We are going for 2oz, no doubt about that.
Nagys,
Do not forget we are having plated thru holes. The pads for the TO-3 still shows tin on the top layer. They are still going to contact the L bracket. Insulation could be simple as putting nylon space 3+5-7mm 1-2 mm thick between the bracket and pcb. All you need extra are the spacers and longer screw for the TO-3s.
Well, what should I say, the nightmare is back again. I hate drilling the bracket for the TO-3s. I had enough with my super leach TO-3 already. But what the hell, that's where the fun is, right? How much more expensive are these compare with the TO-264 (or TO-3P)? Any idea? BTW do Mangatec makes Alfets too?
Should I have the files now? It would be better if I can have both version. And I think we need a vote for the 2 different version. Just like before if we had something like 40-60 (or somewhere near), we can split into 2 group for the purchase. BTW the TO-3 version is about 25cm2 larger, that is going to cost more. An educated guess will be around $2 / pair?
The snapping idea would be the same as dangling wire which had been discussed a couple of post in this thread before. Try to read them.
Krisfr
We are going for 2oz, no doubt about that.
Nagys,
Do not forget we are having plated thru holes. The pads for the TO-3 still shows tin on the top layer. They are still going to contact the L bracket. Insulation could be simple as putting nylon space 3+5-7mm 1-2 mm thick between the bracket and pcb. All you need extra are the spacers and longer screw for the TO-3s.
Well, what should I say, the nightmare is back again. I hate drilling the bracket for the TO-3s. I had enough with my super leach TO-3 already. But what the hell, that's where the fun is, right? How much more expensive are these compare with the TO-264 (or TO-3P)? Any idea? BTW do Mangatec makes Alfets too?
Should I have the files now? It would be better if I can have both version. And I think we need a vote for the 2 different version. Just like before if we had something like 40-60 (or somewhere near), we can split into 2 group for the purchase. BTW the TO-3 version is about 25cm2 larger, that is going to cost more. An educated guess will be around $2 / pair?
Bigpanda - Regarding the vote, can you post that in the Group Buy thread? This way everyone who signed up will read about it.
Awesome idea! The spacers is all that's needed
Alex, please ignore my previous post. This PCB is complete. I would like to kindly ask you to send the generated Gerber files and Sprint files to Bigpanda.
Bigpanda - The bracket is very easy to drill and the reward is a much better sounding amplifier The $2 per pair extra cost is also no big deal, IMO.
Magnatecs and Alfets are identical. Magnatecs sell at Newark and Farnell for around $10 each. Exicons sell at Profusion for around $8 each. Price is nearly identical to the inferior plastic MOSFETS.
Awesome idea! The spacers is all that's needed
Alex, please ignore my previous post. This PCB is complete. I would like to kindly ask you to send the generated Gerber files and Sprint files to Bigpanda.
Bigpanda - The bracket is very easy to drill and the reward is a much better sounding amplifier
The $2 per pair extra cost is also no big deal, IMO. Magnatecs and Alfets are identical. Magnatecs sell at Newark and Farnell for around $10 each. Exicons sell at Profusion for around $8 each. Price is nearly identical to the inferior plastic MOSFETS.
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Hello,
I am sorry for my Endlish!
I have made some simulations with NI Multisim software and because I have not valid spice model for BSS71/74 and 2SJ49/2sk134 i have made simulation with MPSA42/92 and 2sj162/2sk1058 exactly like Nagys suggest in its post 50 from "PCB order for Goldmun clone". OK here is what I found:
1. The Nagy's schematic of Goldmund amp is correct and work perfectly.
2. Lowering the +/-80V at output stage down to +/-50V will NOT LOWER the power of the amplifier and will not increase THD. I think that Goldmund's reason to use 80V is probably sonic performance not measurable. At the some time with +/-80V at high power and 4 Ohm load the output mosfets will go out of power range easily. Probably that's why they use not oversized transformers and only 4700uF capacitors because this will give around 73V at high power and low load. This will be a little bit safer for output mosfets.
3. Lowering 60V AC at input stage will highly increase THD.
Can you please someone check this with simulation again?
Best regards
I am sorry for my Endlish!
I have made some simulations with NI Multisim software and because I have not valid spice model for BSS71/74 and 2SJ49/2sk134 i have made simulation with MPSA42/92 and 2sj162/2sk1058 exactly like Nagys suggest in its post 50 from "PCB order for Goldmun clone". OK here is what I found:
1. The Nagy's schematic of Goldmund amp is correct and work perfectly.
2. Lowering the +/-80V at output stage down to +/-50V will NOT LOWER the power of the amplifier and will not increase THD. I think that Goldmund's reason to use 80V is probably sonic performance not measurable. At the some time with +/-80V at high power and 4 Ohm load the output mosfets will go out of power range easily. Probably that's why they use not oversized transformers and only 4700uF capacitors because this will give around 73V at high power and low load. This will be a little bit safer for output mosfets.
3. Lowering 60V AC at input stage will highly increase THD.
Can you please someone check this with simulation again?
Best regards
Actually you are the one who needs to read the posts before commenting.
The perforated board as I suggested complies with what Jacco said earlier.
Either you have no experience with lateral mosfets or you just enjoy trying to p*ss people off.
What exactly do you want tested then? Sound quality (that would be an opinion)?
I will put it together and see if it works properly, or not. It doesn't matter if I do it, or someone else. As a plus, I have a Tektronix.
Besides, everyone already knows my opinion. It's blatantly displayed in the title of this thread.
I will put it together and see if it works properly, or not. It doesn't matter if I do it, or someone else. As a plus, I have a Tektronix.
Besides, everyone already knows my opinion. It's blatantly displayed in the title of this thread.
I hope that Tektronix is a Mass Spectrometer, a Time Domain Reflectometer and Spectrum Analyzer all rolled into one. I know you know how to use them, ask around if you need some help finding the cold fluxed joints.