Me too. Not sure if the Lundahls are specified for working as choke input...Experience with other Lundahls make me fear buzzing noises in such a topology.
Btw, i couldn't help but notice you are a big R-core fan. May i inquire why? Is this preference sound-related or spec-related?
Hello,
This thread is about to die it seems. A vietnamese friend for whom i brought a pair of LL2733 for choke input a future Nelson Pass amp found a pair of secondhand Tango high current chokes. Because of these having lower mH he will use them as a second choke in a LCLC supply.
Tango can be used as choke input too. See the attachment. You can also see they write a\bout the minimum current needed to make it work as a choke input.
Greetings, Ed
This thread is about to die it seems. A vietnamese friend for whom i brought a pair of LL2733 for choke input a future Nelson Pass amp found a pair of secondhand Tango high current chokes. Because of these having lower mH he will use them as a second choke in a LCLC supply.
Tango can be used as choke input too. See the attachment. You can also see they write a\bout the minimum current needed to make it work as a choke input.
Greetings, Ed
Attachments
Hello,
I cannot read Japanese but it does contain some information. Maybe the non native English speakers are more eager to give other languages a try?
It is surely Japanese. Vietnamese has an alphabet with some letters similar to ours. Chinese looks like those tiny insects in the palm of history by Thomas Dolby.
Why post at all if most people cannot read properly? lol
Greetings, Eduard
I cannot read Japanese but it does contain some information. Maybe the non native English speakers are more eager to give other languages a try?
It is surely Japanese. Vietnamese has an alphabet with some letters similar to ours. Chinese looks like those tiny insects in the palm of history by Thomas Dolby.
Why post at all if most people cannot read properly? lol
Greetings, Eduard
Hi All
The thread is not dead yet, just on hold until i have gathered all the necessary parts. Every month when i get paid i purchase the parts i need. Presently i have now sourced someone to make a build me a R-Core transformer!
So please be patient next few months i should have everything purchased ready to build!
Just finishing building some mini onken speakers! Will post my progress.
The thread is not dead yet, just on hold until i have gathered all the necessary parts. Every month when i get paid i purchase the parts i need. Presently i have now sourced someone to make a build me a R-Core transformer!
So please be patient next few months i should have everything purchased ready to build!
Just finishing building some mini onken speakers! Will post my progress.
vishalk,
you can get them here
Audio Catalog
I havent bought from them before, but i've bought chinese r-cores like these for preamps before. They can be custom made to include quite a few taps, it seems.
you can get them here
Audio Catalog
I havent bought from them before, but i've bought chinese r-cores like these for preamps before. They can be custom made to include quite a few taps, it seems.
regarding jims_audio boards I have two questions:
1) are the parts ok? Specially the transistors.
2) i believe the version to go for is the one without the kubota reg, is this right?
There is also a serbian seller which has the "classe a" and "le monstre", any comments on his boards/kits?
1) are the parts ok? Specially the transistors.
2) i believe the version to go for is the one without the kubota reg, is this right?
There is also a serbian seller which has the "classe a" and "le monstre", any comments on his boards/kits?
Hi
Can anyone help me identify if this amplifier is the Hiraga 30W or not? Its a DIY amplifier I purchased from ebay a few years ago.
I'm pretty sure it's not the lowest power Hiraga amp.
Also note in the pics the components are not the best so I'm wondering if anyone knows what can be done to upgrade this lovely sound machine ?
The power supply can be upgraded for sure to a mains supply, at the moment its running from a Car battery to SMPS, the sound is great but the bass is lacking bottom end.
Its sounding very good at the moment but I wonder what the capacitor and resistor do near the outputs ? the amp is mellow at the top end but perhaps a bit too mellow for me.
The capacitors and resistors look kind of generic ? I would upgrade them all but im not sure what schematic I should be going by, is this the 20w or 30w amp thats the question!
What I do know is the F5 by Nelson Pass when I heard it sounded better than this yet this has a nice mellow charm to it.
Can anyone help me identify if this amplifier is the Hiraga 30W or not? Its a DIY amplifier I purchased from ebay a few years ago.
I'm pretty sure it's not the lowest power Hiraga amp.
Also note in the pics the components are not the best so I'm wondering if anyone knows what can be done to upgrade this lovely sound machine ?
The power supply can be upgraded for sure to a mains supply, at the moment its running from a Car battery to SMPS, the sound is great but the bass is lacking bottom end.
Its sounding very good at the moment but I wonder what the capacitor and resistor do near the outputs ? the amp is mellow at the top end but perhaps a bit too mellow for me.
The capacitors and resistors look kind of generic ? I would upgrade them all but im not sure what schematic I should be going by, is this the 20w or 30w amp thats the question!
What I do know is the F5 by Nelson Pass when I heard it sounded better than this yet this has a nice mellow charm to it.
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Which one is running;-?
The silver-board-amp may be a Hiraga Classe A; 4 complementary-parts-stages, some resistors I recognize, no JFet-input (Le Monstre)
The silver-board-amp may be a Hiraga Classe A; 4 complementary-parts-stages, some resistors I recognize, no JFet-input (Le Monstre)
The green/blue board is SMPS original power supply and car amplifier chassis. It was originally a car amplifier then modified with Hiraga (silver and board)
Thanks for the help, I'll have a study of Classe A..
Better photos tomorrow 🙂
Thanks for the help, I'll have a study of Classe A..
Better photos tomorrow 🙂
It's been a while since i've been on here, the project took a major halt after funds become low and my wife gave birth to our first child!
But it's time to get this going again now things are settled and better.
So the last time i was sourcing all my power supply bits. You'll be glad to know i finally found a pair of R core trannies!
These things are massive and weigh quite a bit! I paid £200 for the pair, new and unused.
500va 2x24v which really is going to be perfect for my needs. Next thing is to source and buy all the capacitors!
But it's time to get this going again now things are settled and better.
So the last time i was sourcing all my power supply bits. You'll be glad to know i finally found a pair of R core trannies!
These things are massive and weigh quite a bit! I paid £200 for the pair, new and unused.
500va 2x24v which really is going to be perfect for my needs. Next thing is to source and buy all the capacitors!
warning with the hiragas!
like naims, if you do not have the original transistors (NEC, toshiba, hitachi, Cosmos)(depending on the versions ) and the good supply that goes with it, it will sound, but not hiraga sound.
it's one of those amps that really needs a lot of attention (kaneda school ...)
a good synthesis in french(sorry)
http://bjl.audioconcept.free.fr/Arc...lis_Transistors/Hiraga/Hiraga_20w_class_a.pdf
like naims, if you do not have the original transistors (NEC, toshiba, hitachi, Cosmos)(depending on the versions ) and the good supply that goes with it, it will sound, but not hiraga sound.
it's one of those amps that really needs a lot of attention (kaneda school ...)
a good synthesis in french(sorry)
http://bjl.audioconcept.free.fr/Arc...lis_Transistors/Hiraga/Hiraga_20w_class_a.pdf
Can I know where we can buy these R core transformers in EU, I can't find those French Selectronics anymore. 🙁
selectronic are closed last year
you can find exactly the same transformer in 250VA in A3i cambridge
for spare parts.
moreover, the period is propitious, all this generation of this amp dies one after the other
you can find exactly the same transformer in 250VA in A3i cambridge
for spare parts.
moreover, the period is propitious, all this generation of this amp dies one after the other
I know it's such a shame, unfortunately the company closed 🙁 this is why i bought these, i had great difficulty finding a company to make these for me. It would have cost me over £500.
I agree, this is why i am making a suitable big power supply! It's hard to find the original transistors, but the members on here have tried and tested other suitable replacements with success, please read through the threads.
This amplifier will get the best parts available with attention to detail. There is some really good advice on here.
I now have the lundhal chokes and the transformers, so we are getting there slowly but surely.
Remove the busbars. Replace with 0,8 mm solid core.
Remove any MKPs. Use the big caps only.
Remove the original wires. Replace by possible min. solid cores or laqueured litzwire.
Remove the solder joints. Set new ones, min. solder, min. diameter!
Replace the power-resistors. Use film-resistors. Psu too!
And so on, and so on, and so on.
Remove any MKPs. Use the big caps only.
Remove the original wires. Replace by possible min. solid cores or laqueured litzwire.
Remove the solder joints. Set new ones, min. solder, min. diameter!
Replace the power-resistors. Use film-resistors. Psu too!
And so on, and so on, and so on.