Member
Joined 2002
Russ White said:
May i ask if you got my important email and if it will help on this new or thread ?
steenoe said:
Dear Sir,
maybe I am slightly off-topic here but I can tell you about my humble experience with a BOZ.
Actually I placed a 50K blue Alps pot at the input.
In this way, as Mr. Pass says in his excellent article, you get all the noise from the power supply directly to the power amp.
But if you succeed in doing the PS very well the sound is very very good, even in the unbalanced version (i.e. BOZ).
Actually I am using this BOZ for testing some different 0-60V single power supply design to select the best.
I can even hear the effect of a single filter cap change !
Very powerful tool.
But for the balanced version the power supply noise maybe is not such fundamental problem as it really is in the BOZ.
Kind regards,
beppe61
Avel trafos tested - success!
So I got the trafos from Avel in yesterday, finally had to time to run them in for more than 3 hours.
I have had the pair of trafo driving two PS and two preamps. AC voltages in my tests are 66.4VAC and 27VAC and the DC rails are at +73VDC -19.1VDC. The PS heatsinks get nice and warm but not at all what I would call hot. The 1.5K resistors on the preamp on the other hand get nice and toasty, so make sure you raise them up off the PCB at least 1/2" or so and probably more like 3/4" when you build.
The preamp heatsinks get warm so you know its doing its job, but it could probably handle twice the load. 🙂
Sounds very good with SE in SE out right now for testing, soon I will have the thing in a proper case for real testing. 🙂
more than 3 hours burning in and nothing has blown up, so I feel pretty good.
For now I am pleased. 😀
Cheers!
Russ
So I got the trafos from Avel in yesterday, finally had to time to run them in for more than 3 hours.
I have had the pair of trafo driving two PS and two preamps. AC voltages in my tests are 66.4VAC and 27VAC and the DC rails are at +73VDC -19.1VDC. The PS heatsinks get nice and warm but not at all what I would call hot. The 1.5K resistors on the preamp on the other hand get nice and toasty, so make sure you raise them up off the PCB at least 1/2" or so and probably more like 3/4" when you build.
The preamp heatsinks get warm so you know its doing its job, but it could probably handle twice the load. 🙂
Sounds very good with SE in SE out right now for testing, soon I will have the thing in a proper case for real testing. 🙂
more than 3 hours burning in and nothing has blown up, so I feel pretty good.
For now I am pleased. 😀
Cheers!
Russ
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Joined 2002
The first of the kits should be arriving today or tomorrow (US buyers), so I though I'd mention a few things about the kits.
The kit contains, in addition to the boards, 5 seperate bags of parts.
One contains all the hardware for the kit. Inside are the ps heatsinks and two smaller bags. One is the pre hardware and one is the ps hardware (standoffs & screws, thermal pads, PCmount faston tabs, faston crimp connectors, and screw/shoulder washers/nuts for FET mounting). The only 'mixed parts' are the thermal pads, which, because of the way they were shipped to me, all the pads for both PS and PRE together. I think you can figure that out. 😉
There are two bags of PRE parts, one per channel. Inside each are the caps, and another smaller bag with the resistors and diodes, and a small piece of rail with the 5 matched fets. Everything is labeled. To save a little time with the kit, a few of the labels list two parts and you will find two of them. For example the 1uF Wimas each have a label that says C9 & C10, but one is C9 and one is C10. Again, I think you can figure this out.
The PS bags are much the same, one per channel, containing caps, and a sub bag with the diodes/resistors/jumpers, and a small piece of rail with the 610 and 9610 fets (together). Again, each part is labeled.
For those who got the Dales, they are all in a single bag (both channels, PS and PRE). You will find two of each part, one for each channel. Since the PRE and PS use some of the same names, the PS resistors have either a blue or red line on the label to differentiate them.
Now that the first batch of Solens are in and I have enough caps to build my own boards (need to remove the 2 Jantzens I have as I only have 3 total), I will be building my second set and photographing for a build guide, bt that likely won;t be dine until after the new site it up.
One tip for building off the top of my head... if you mount all the fastons first, they provide a nice space for mounting the 2W and 3W resistors when the board is upside down, and you can easily get all the resistors at the same height.
If you have build questions, it's better to ask them here than to send email, so others can see the answers. Have fun!
The kit contains, in addition to the boards, 5 seperate bags of parts.
One contains all the hardware for the kit. Inside are the ps heatsinks and two smaller bags. One is the pre hardware and one is the ps hardware (standoffs & screws, thermal pads, PCmount faston tabs, faston crimp connectors, and screw/shoulder washers/nuts for FET mounting). The only 'mixed parts' are the thermal pads, which, because of the way they were shipped to me, all the pads for both PS and PRE together. I think you can figure that out. 😉
There are two bags of PRE parts, one per channel. Inside each are the caps, and another smaller bag with the resistors and diodes, and a small piece of rail with the 5 matched fets. Everything is labeled. To save a little time with the kit, a few of the labels list two parts and you will find two of them. For example the 1uF Wimas each have a label that says C9 & C10, but one is C9 and one is C10. Again, I think you can figure this out.
The PS bags are much the same, one per channel, containing caps, and a sub bag with the diodes/resistors/jumpers, and a small piece of rail with the 610 and 9610 fets (together). Again, each part is labeled.
For those who got the Dales, they are all in a single bag (both channels, PS and PRE). You will find two of each part, one for each channel. Since the PRE and PS use some of the same names, the PS resistors have either a blue or red line on the label to differentiate them.
Now that the first batch of Solens are in and I have enough caps to build my own boards (need to remove the 2 Jantzens I have as I only have 3 total), I will be building my second set and photographing for a build guide, bt that likely won;t be dine until after the new site it up.
One tip for building off the top of my head... if you mount all the fastons first, they provide a nice space for mounting the 2W and 3W resistors when the board is upside down, and you can easily get all the resistors at the same height.
If you have build questions, it's better to ask them here than to send email, so others can see the answers. Have fun!
Just received your package...Twisted Pear did an absolutely beautiful job organizing this and getting it packed up....
I appreciate the effort! Thank you!
rt
I appreciate the effort! Thank you!
rt
Received my order today, 4 days from the States to the UK. Many thanks to all involved - great work.
Cheers
Bruce
Cheers
Bruce
Good work indeed🙂 Thats a nice little "package" on the picture. Pretty compact. Two of those packages would fit nicely in a standard chassis🙂 I am still very happy with the proto I made. The preamp played lots of hours, and nothing burned in mine either😀 Well, I guess you can see an occasional device failure, but besides that I think the circuit is stable🙂 Very good preamp, to say the least😉
Steen😎
I'd be interested in hearing how well the packing held up during shipping. I want to know if I need to change the way I am packing things...
BrianDonegan said:
I received mine today. I haven't unpacked all of the bags yet but I did notice that the pins on the electros are bent over. Not a big deal. I suppose you could stick a little bit of foam over them.
Blessings, Terry
Brian, got my package yesterday. It was in perfeckt condition, and I was impressed by the way you packed it all together.
Trygve
Trygve
Dear Sirs,
please excuse my intromission but I would like to know if there is any post (number?) that reports some listening impressions of these wonderful preamp (or comparison to other preamps, DIY and commercial).
I searched the thread but have been overwhelmed by the number of posts.
Thank you so much.
Kind regards,
beppe
P.S. really great product. Congratulations!
please excuse my intromission but I would like to know if there is any post (number?) that reports some listening impressions of these wonderful preamp (or comparison to other preamps, DIY and commercial).
I searched the thread but have been overwhelmed by the number of posts.
Thank you so much.
Kind regards,
beppe
P.S. really great product. Congratulations!
beppe61 said:
who cares how it sounds?
it looks awesome
and local boyz just like looong threadsssss...
just look at number of OT posts
choky said:
> who cares how it sounds?
Dear Sir,
I believed that was the purpose.
> it looks awesome
Absolutely no doubts about this.
Very fine piece of technology.
> and local boyz just like looong threadsssss...
just look at number of OT posts
I see.
So any chance to hear about a listening shoot-out or even short listening impressions?
I would be very interested.
Thank you very much.
Kind regards,
beppe