I'm probably going to start with the two 600VA approx ±80V (on load and at 253V mains AC) with maybe ± 90V regulated early stages. Heat sinks are already drilled for 6 pairs and for 8 pairs of single die mosfets.
I'll start with the 8 pairs and the Nichicon GS caps for greatest effect when demonstrating them to friends. For comparison I'll drop in two ± 100v 1kVA Tx's but be careful to not clip the output during playing loud. If they are better sounding, using them will be an issue with not being able to go much above the suggested ±85 for the LME49830.
I'll be wanting to run a much lower bias too, maybe 80mA per pair (not using the double die Alfets). My pal could not hear any difference between that bias and twice that (not using the double die Alfets). Maybe that will not be the case when using this LME chip. I personally won't want to be wasting that much electricity (360mA per pair) so I'll have to see what it sounds like with lower bias and if that is worse than a discrete component circuit.
If these chip early stage amps really blow the doors of the 300W mono blocks then I'll consider having the 1KVA's rewound with a bit less voltage if I can be satisfied with a bit less overhead.
The main reason I haven't already got a pair going is that I need to buy the parts and from the USA as the UK doesn't stock all that much these days. Mouser will be the place, it looks like, to minimise post, etc. I need to get all the other little bits for the teddy regs, or whatever. I've not completed the parts list yet.
I'll start with the 8 pairs and the Nichicon GS caps for greatest effect when demonstrating them to friends. For comparison I'll drop in two ± 100v 1kVA Tx's but be careful to not clip the output during playing loud. If they are better sounding, using them will be an issue with not being able to go much above the suggested ±85 for the LME49830.
I'll be wanting to run a much lower bias too, maybe 80mA per pair (not using the double die Alfets). My pal could not hear any difference between that bias and twice that (not using the double die Alfets). Maybe that will not be the case when using this LME chip. I personally won't want to be wasting that much electricity (360mA per pair) so I'll have to see what it sounds like with lower bias and if that is worse than a discrete component circuit.
If these chip early stage amps really blow the doors of the 300W mono blocks then I'll consider having the 1KVA's rewound with a bit less voltage if I can be satisfied with a bit less overhead.
The main reason I haven't already got a pair going is that I need to buy the parts and from the USA as the UK doesn't stock all that much these days. Mouser will be the place, it looks like, to minimise post, etc. I need to get all the other little bits for the teddy regs, or whatever. I've not completed the parts list yet.
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no i don`t.
it`s not only the supplies.
my speakers are power hungry but 600watt is enough so no need for third pair.
two pairs will dissipate 80-90 watt and i can leave with that.
the power supplies (one per channel) are connexelectronic A1000SMPS
1100watt continues adjustable 75-90volt.
IanAS, if you log into Digikey from the UK site, not digikey.com but probably digikey.com.uk (or co.uk maybe, look it up) you pay very slightly more for parts, but order over 200 dollars worth and just like mouser the shipping is free. many parts are still slightly cheaper at digikey
this is only a fairly recent development
this is only a fairly recent development
Thanks qusp, I was wondering about that. I think it might be £50 for free delivery from Mouser, so that's a bit easier to achieve. There are a few parts in my list that only DK has though. The other year I did get free del with a $110 order, I didn't know if that only applied to that part. Or perhaps it was $100 of any single part number. There's the other issue with import taxes. All payable with DK but Mouser UK were saying I might not have to pay all of the tax. I've forgotten. Not ordered from Mouser before. Nearly everyting I look at at Farnell is out of stock or USA stock meaning they add a £20 import fee to that part price.
Component buying of small quantities is a difficulty. For many items I have maybe 6 part numbers and prices from the various suppliers.
Component buying of small quantities is a difficulty. For many items I have maybe 6 part numbers and prices from the various suppliers.
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Thanks Paul, that's good to know as I have nearly much I need from them.
Last year, or so, a UK sales person at Mouser said to me, "Choose Fedex Int Priority so only get charged VAT and not customs or admin". Basically that would save the £10 'admin' we have to pay if the ex-VAT bill is more than £15. As far as I can make out the duty is goods specific and applies to an ex-vat bill that is larger, eg, over £150. The amount of duty varies with the items and electronic good attract a much higher duty that some others.
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Notes
Hi ,
@ Opc:
We have problem on network at MDI then not receive email. also, UPS ship for dps-400+pbtu-2 for wire Amp wait in office. i change now corrier to "Bartolini spa" fast package. think deliver in 2-3 days max.
sorry for this disage.
------------------------------
@ diy:
If all is ok, first lot (both model) are ready for custom Wire Amp.
Best Regards
Roberto
Hi ,
@ Opc:
We have problem on network at MDI then not receive email. also, UPS ship for dps-400+pbtu-2 for wire Amp wait in office. i change now corrier to "Bartolini spa" fast package. think deliver in 2-3 days max.
sorry for this disage.
------------------------------
@ diy:
If all is ok, first lot (both model) are ready for custom Wire Amp.
Best Regards
Roberto
Hi Guys,
Just a quick mosfet update. I've been in contact with Richardson RFPD and it looks like they have a confirmation that they will receive the N channel mosfets this week, but they are still struggling to get a lead time on the P channel devices. The issue has apparently been escalated and they have promised me an answer shortly, and they "estimate" first week of April.
My best guess is that Semelab diffused the N channel parts first and will run the P channel devices after, which seems to align with the dates provided.
The good news is that absolutely every kit has been packed, addressed, and had the customs forms filled out, so I can literally send everything off the day I get the fets. I've attached a picture of my neatly organized audio cabinet (unfortunately the rest of my office isn't so neatly organized!).
Sorry again to everyone for the delays, but it looks like we're in the home stretch now.
As a side note, is there anyone who wants more mosfets than they currently have? I'm debating placing another order for another 100 of each type of fet while they're available, in order to have some extra on-hand should anyone blow something up or need more.
Let me know if anyone wants some extra...
Regards,
Owen
Just a quick mosfet update. I've been in contact with Richardson RFPD and it looks like they have a confirmation that they will receive the N channel mosfets this week, but they are still struggling to get a lead time on the P channel devices. The issue has apparently been escalated and they have promised me an answer shortly, and they "estimate" first week of April.
My best guess is that Semelab diffused the N channel parts first and will run the P channel devices after, which seems to align with the dates provided.
The good news is that absolutely every kit has been packed, addressed, and had the customs forms filled out, so I can literally send everything off the day I get the fets. I've attached a picture of my neatly organized audio cabinet (unfortunately the rest of my office isn't so neatly organized!).
Sorry again to everyone for the delays, but it looks like we're in the home stretch now.
As a side note, is there anyone who wants more mosfets than they currently have? I'm debating placing another order for another 100 of each type of fet while they're available, in order to have some extra on-hand should anyone blow something up or need more.
Let me know if anyone wants some extra...
Regards,
Owen
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