For Onetics - one needs to PM BudP. There is no website. They mostly do OEM work.
I have asked Cinemag to tell me if they have issue sending out of US, and have asked them to be more responsive to these requests. A group buy is possible for these, but I dont think it would end up saving anyone money with double shipping and paypal charges etc.
I have asked Cinemag to tell me if they have issue sending out of US, and have asked them to be more responsive to these requests. A group buy is possible for these, but I dont think it would end up saving anyone money with double shipping and paypal charges etc.
I ordered the H or high nickel version. That doesn't necessarily mean it will sound any better than the 50 percent version - which is a closer match 'nickel-wise' to the Jensen.
To me these represent likely the least priced version.
I have built some boards that are almost complete that represent the "Unbuffered F6".
The main goal here is to start really evaluating listening of the transformers, without the ability to tweak anything else. I hope to have the whole thing wired into a listenable fashion in a few days. It's a busy time of year as we all know!
I contacted David at Cinemag - they are very behind in emails, as they have had some colds spreading around the company. He assured that they will get to all of them, and will ship anywhere legal to ship to using Fedex, DHL, post office UPS etc. So that should cover it.
To me these represent likely the least priced version.
I have built some boards that are almost complete that represent the "Unbuffered F6".
The main goal here is to start really evaluating listening of the transformers, without the ability to tweak anything else. I hope to have the whole thing wired into a listenable fashion in a few days. It's a busy time of year as we all know!
I contacted David at Cinemag - they are very behind in emails, as they have had some colds spreading around the company. He assured that they will get to all of them, and will ship anywhere legal to ship to using Fedex, DHL, post office UPS etc. So that should cover it.
Here is some pictures showing my implementation of the Unbuffered F6.
This shows all available jumpers, except now the Toshiba JFETs 2SK and 2SJ no longer need the source resistor spot jumpered.
To be specific, pots are jumpered to the middle pin towards the source resistor, the source resistor itself is jumpered, one led is jumpered, and the input is jumpered all the way to the input of the transformer, which is on the remote end of R11,12.
This shows all available jumpers, except now the Toshiba JFETs 2SK and 2SJ no longer need the source resistor spot jumpered.
To be specific, pots are jumpered to the middle pin towards the source resistor, the source resistor itself is jumpered, one led is jumpered, and the input is jumpered all the way to the input of the transformer, which is on the remote end of R11,12.
Attachments
Here is the proposed mouting for Universal Specification if you have one of the store chassis.
The FETs would go into red or blue postitions. If its in the blue , you can mount one set of standoffs in the green area direct to chassis.
Since the mounting on the blue taps will leave the board very close to the bottom of the chassis - I cannot guarantee that it fit there. We just made it under the limits of the proposed area.
If anyone already has these chassis, let me know - I can send you physical print out to measure against the actual chassis.
The FETs would go into red or blue postitions. If its in the blue , you can mount one set of standoffs in the green area direct to chassis.
Since the mounting on the blue taps will leave the board very close to the bottom of the chassis - I cannot guarantee that it fit there. We just made it under the limits of the proposed area.
If anyone already has these chassis, let me know - I can send you physical print out to measure against the actual chassis.
Attachments
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Hello, did a beautiful job.
He liked to ask some questions:
- Li behind which has a power of +- 37W in speaker 8ohms?
- With these changes is maintained in the 37W Class A (8ohms)?
- Do not want to use the 2SK/2J74 with IDSs larger than 8mA?
thank you
He liked to ask some questions:
- Li behind which has a power of +- 37W in speaker 8ohms?
- With these changes is maintained in the 37W Class A (8ohms)?
- Do not want to use the 2SK/2J74 with IDSs larger than 8mA?
thank you
Blink - What changes are you talking about to the design?
If higher IDSS than 8ma, Nelson suggest using 10R degeneration resistors.
If higher IDSS than 8ma, Nelson suggest using 10R degeneration resistors.
I have the 4U "Deluxe" chassis on hand (the pre-drilled version), for my in progress F5 build. I'd be happy to check things out if you'd like.
If its like F5T boards, it will fit fine. Still advise mounting fets to ink before soldering to board. This makes certain that coupling to sink is optimal.
So some good news.
6Speed has helped me with the layout in an actual diyAudioStore chassis.
We shaved a few mm off the bottom to get it to clear without issue. I may see if we can do a little more, so the board so will have a little more clearance.
There has been a new source of R100's and R100A's available. His name is Semisouthfan on diyaudio. Check out the post by him below.
http://www.diyaudio.com/forums/pass-labs/222098-semisouth-goes-dodo-what-now-2.html#post3295645
He is asking 50.00 per device for these. All things considered, no getting around it - a fair price I guess considering they are obsolete. I beleive they are unmatched.
Lastly, I have 'mule' test amp running in chassis, running in my main rig. This will allow me to evaluate the sound of the transformers a bit more.
I tried running the unbuffered version. while it ran in my bench, the output from my x-over I guess did not match. Running with buffer seems the way to go!
6Speed has helped me with the layout in an actual diyAudioStore chassis.
We shaved a few mm off the bottom to get it to clear without issue. I may see if we can do a little more, so the board so will have a little more clearance.
There has been a new source of R100's and R100A's available. His name is Semisouthfan on diyaudio. Check out the post by him below.
http://www.diyaudio.com/forums/pass-labs/222098-semisouth-goes-dodo-what-now-2.html#post3295645
He is asking 50.00 per device for these. All things considered, no getting around it - a fair price I guess considering they are obsolete. I beleive they are unmatched.
Lastly, I have 'mule' test amp running in chassis, running in my main rig. This will allow me to evaluate the sound of the transformers a bit more.
I tried running the unbuffered version. while it ran in my bench, the output from my x-over I guess did not match. Running with buffer seems the way to go!
I am discussing with SemiSouthfan about getting some of these in quantity and matching them. With that said, I am going to open up my SemiSouth waiting list again.
One can certainly tell the difference between transformers.
The question than becomes which one sounds best?
Initial impressions only listening to Vinyl of Neil Young - "after the gold rush"
The Jensen sounds delicate and with a relaxed tone to it.
The Onetics sounds more forward, discrete, closer to clinical, and less colored. It almost sounds a little clearer, but the Jensen does not hide anything I don't think.
The amp itself, regardless of transformer has a very wide soundstage, and a fair amount of depth to it. I don't think it sounds like other Firstwatt clones at this point.
The question than becomes which one sounds best?
Initial impressions only listening to Vinyl of Neil Young - "after the gold rush"
The Jensen sounds delicate and with a relaxed tone to it.
The Onetics sounds more forward, discrete, closer to clinical, and less colored. It almost sounds a little clearer, but the Jensen does not hide anything I don't think.
The amp itself, regardless of transformer has a very wide soundstage, and a fair amount of depth to it. I don't think it sounds like other Firstwatt clones at this point.
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