i'm on a roll... the kgsshv

[justin]

Do a search in the T2 thread for "Dalbani". Buyer beware!

doh. the ones in the eBay pic look real though. all the 2SA1968 fakes ive seen are clearly fake if you've seen a real one.

edit: i thought the Dalbani name was familiar, but the ebay link says they're in Florida, so i thought it was someone else

Edited August 23, 2012 by justin

[livewire]

I just bought some real ones. From BDent for ~$8.60 each. Get what you pay for.

[justin]

i remember when mikhail had a couple thousand 2SA1968. i'm sure the price from Sanyo was in the 20-40 cents range. he just bought any parts he might someday use -- that was when he was going to build a point to point Blue Hawaii. wonder what happened to them..

Edited August 23, 2012 by justin

[livewire]

I've read that Dalbani also has offices / warehouses in the UK, Lebanon and Dubai.

Edited August 23, 2012 by livewire

[SoupRKnowva]

2.1v - vbe junction (.7) /180 ohms == 7ma.

But the led's actually are more like 1.7 volts due to

the drive current.

So its about 5.5ma.

You can change to a higher voltage led, but the red led's thermally

match the output transistors.

So you want to cut the 180 ohm resistors to something like 150 or 120 ohms.

So could you replace the emitter resistor with a like 200 ohm trimmer resistor so you don't have to solder and re solder to test different biases?

[justin]

100 ohm resistor + 100 ohm trim pot is a much better idea

[Victor Chew]

i remember when mikhail had a couple thousand 2SA1968. i'm sure the price from Sanyo was in the 20-40 cents range. he just bought any parts he might someday use -- that was when he was going to build a point to point Blue Hawaii. wonder what happened to them..

Mikhail must have bought those more than 10 years ago. That is real foresight if he had investments in his mind. Outperforms many other forms of investments and they don't have to be fed as well. Under the bed will be a good enough storage.

People like us who really need them today will have to pay the much higher prices unfortunately.

Edited August 23, 2012 by Victor Chew

[justin]

oh yeah, i'm kicking myself when i see quotes i have from 2002-2005 on 2SK389/2SJ109. less than $1 each and thats only at qty of a few hundred.

[justin]

That is real foresight if he had investments in his mind. Outperforms many other forms of investments and they don't have to be fed as well. Under the bed will be a good enough storage.

depends if they're to be used instead of paying higher prices later, or to be sold later for a profit. factor in the time/labor of unloading the parts 1, 2, or 5 at a time, probably over several years

[arnaud]

Humm, "silicon" gold

[spritzer]

That's what I keep telling myself when I buy these large lots.

WRT upping the HV bias keep in mind just how far the transistors can be pushed. 20mA at 500V is a lot of power and the PSU needs to be oversized as well. My plan is to lower the rails to 400-450V and increase the current that much more.

[eggil]

Well, I bought 10 mainly out of curiosity. I will take pictures when they arrive and will test them with my limited equipment and will compare them with the ones I got from BDent

If they are fakes they'll go back where they came from.

If they give me a hard time, then it will reflect in their feedback.

Edited August 24, 2012 by eggil

[SoupRKnowva]

WRT upping the HV bias keep in mind just how far the transistors can be pushed. 20mA at 500V is a lot of power and the PSU needs to be oversized as well. My plan is to lower the rails to 400-450V and increase the current that much more.

Wouldn't team overkill just use two power supplies rather than compromise like that?

[kevin gilmore]

dual mono for the win.

2 amplifer boards

2 power supply boards

2 transformers

monster sized box(s)

[spritzer]

I do have two 450V transformers in stock so that would be workable. Perhaps we should take the T2 psu board and adapt it to the HV for offboard sinks? I'm also going to cut the onboard pcb files down in size when I have time.

[SoupRKnowva]

The wheels had already been turning in my head on this one after you said that about the power supply Spritzer, and i think you could pretty easily fit two power supplies and transformers into the 2U pessante case to stack nicely underneath the 3U Pessante Dissipante case the amp would be in. But an offboard version would be pretty cool as well...

This was also super convenient because now I'll have room for the AMB Delta 1 attenuator(since i missed out on the KG one) inside the amp case, i was wanting to use a couple of them, but couldn't find the room.

[johnwmclean]

I like this idea, it oozes overkill.

[jcx]

dual mono isn't "overkill" with Class A balanced output - it is closer to "not even wrong"

Class A balanced output draws constant current from the PS - there isn't any interaction between channels via the PS if they are both ~ ccs loads irrespective of audio signal in either channel

even in clipping the most common situation will be Voltage clipping - low frequency audio signals don't draw any appreciable current drivng ES, are the most common large amplitude signals

[cobra_kai]

Now we just need a dual mono T2

[kevin gilmore]

But the amplifier part is in fact completely dual mono. Was from the start.

2 completely seperate power supply umbilicals.

Just in case someone wanted to make dual power supplies.

see... i think ahead.

[Victor Chew]

Infact I did run this dual mono thingy by Kevin some time ago. He probably thought that I was a bit mad and by way of his "medicinal cure for me" he siad it was way over kill for a headphone amp but that it was ok for a speaker amp. I was cured and did not proceed with the dual mono idea. But I think the medicinal effect is not permanent, and I feel that my madness is coming back. Not only for the KGSShv but hopefully for the megatron as well. Infact the dynahi I am building now is dual mono. Do I really want to be cured or can I be?

[justin]

what you need to do is build the DC servo out of another dynahi, you know for symmetry. then you have to build the servo for the servo out of another dynahi. this would continue forever.

[nattonrice]

The New Fractal Dynahi, now shipping from Head-Case.

[wink]

With infinite loop technology + local feedback.

[gustavo.skn]

Could you guys tell me how much did you spend in your kgsshv build?

Thanks