Hi all I haven't been soldering in many years now....but....
I need a preamp for my Pass F5 I built years ago, just as it is not quite loud enough. I have looked into the prospect of building a slightly more powerful version, but I'm not sure my heat sinks will be up to it, and the amp is so stable and reliable I don't want to mess with it.
I found this PCB for a "Pass 2.0" preamp on eBay. I wonder if this is the unbalanced version of the famous P 1.7 preamp??
SE class A MOSFET unbalanced + 128 step volume control preamplifier PCB ! | eBay
Any ideas? Thanks
Lucas
I need a preamp for my Pass F5 I built years ago, just as it is not quite loud enough. I have looked into the prospect of building a slightly more powerful version, but I'm not sure my heat sinks will be up to it, and the amp is so stable and reliable I don't want to mess with it.
I found this PCB for a "Pass 2.0" preamp on eBay. I wonder if this is the unbalanced version of the famous P 1.7 preamp??
SE class A MOSFET unbalanced + 128 step volume control preamplifier PCB ! | eBay
Any ideas? Thanks
Lucas
IP meaning intellectual property?
Sure, I get that. It sucks when a product is recently out and is cloned and commercialised already and their profits are hit. But, this design isn't available to buy legit, is it?
Plus, isn't that the way technology evolves? People steal ideas and adapt and learn and improve and simplify. A LOT of that happens on DIY Audio. The production of a PCB in China is merely a furthering of that trend.
Sure, I get that. It sucks when a product is recently out and is cloned and commercialised already and their profits are hit. But, this design isn't available to buy legit, is it?
Plus, isn't that the way technology evolves? People steal ideas and adapt and learn and improve and simplify. A LOT of that happens on DIY Audio. The production of a PCB in China is merely a furthering of that trend.
I've got a Pass 1.7 clone and there are some similarities but it is not possible to tell without more details.
The P1.7 is a nice pre-amp, I use it with my Aleph 4 to increase the gain as you suggest.
I built a nice RCA - XLR convertor to match my standard components to the balanced inputs of the P1.7 and Aleph 4.
The P1.7 is a nice pre-amp, I use it with my Aleph 4 to increase the gain as you suggest.
I built a nice RCA - XLR convertor to match my standard components to the balanced inputs of the P1.7 and Aleph 4.
Why is that? I am genuinely interested. Is it Jims Audio specifically that is the problem, do you think, or is there a cultural disdain on DIYAudio for any Chinese made PCBs of Nelson Pass's designs? If an individual were to make their own PCB o the same design would that also be frowned upon?
I completely understand the discomfort around commercialisation of somebody else's intellectual property, but would personally only actually boycott these products if they competed against the inventor's own sales.
Well, theft is theft. Then there is reputation. What if this guy's product is problematic or underperforms and it creates a bad name to something which he offers as Pass?
Apart from any issues around IP there is the simple fact that an ebay seller has products for sale but provides no technical support or opportunity for discussion of their product.
Yet there is the expectation that the generous folk on this forum will provide the support to make such products viable and hence support that seller?
Compare that to the fully supported situation where you purchase from the diyAudio store or an approved group buy on this forum.
Yet there is the expectation that the generous folk on this forum will provide the support to make such products viable and hence support that seller?
Compare that to the fully supported situation where you purchase from the diyAudio store or an approved group buy on this forum.
Well, I'd say there's theft, and then there's theft. It's not all the same at all.
Are you saying that nobody should build an Aleph L preamp for evermore? Unless they make their own PCB? Unless they do it point to point?
I'm very happy that somebody is making such high quality PCBs. I simply wouldn't be able to attempt such an amp otherwise.
He offers a schematic and parts list.
Surely members on this forum that offer their generous help would be supporting the humble DIY audio maker, not really supporting the maker of the PCBs from the country with the very lax IP laws.
DIY audio store has a very limited stock and range of PCBs. I have bought loads of them in the past and they're great, but so are others, including Jim's Audio.
Well, I guess I have to break a lance for Jims Audio.
I know this guy for about 30 years, he is reliable. It's easy to grade all Chinese eBay sellers similar, but this shop is the only one, where I would buy for example Toshiba 2SK170 (if offered). He never ever would sell fakes. Thats also visible with his 100% positive Feedback.
And he will send appropriate schematic and part list with every buy per mail.
Sure, he doesn't show these with the auction, gues why.
Another pot of tea is selling PCB's and sets for Pass amps, but as far as I know, he doesn't sell e.g. PCB's for J2. But for F2 with some nice ideas implemented.
Just my 10 Cents.......
I know this guy for about 30 years, he is reliable. It's easy to grade all Chinese eBay sellers similar, but this shop is the only one, where I would buy for example Toshiba 2SK170 (if offered). He never ever would sell fakes. Thats also visible with his 100% positive Feedback.
And he will send appropriate schematic and part list with every buy per mail.
Sure, he doesn't show these with the auction, gues why.
Another pot of tea is selling PCB's and sets for Pass amps, but as far as I know, he doesn't sell e.g. PCB's for J2. But for F2 with some nice ideas implemented.
Just my 10 Cents.......
Leaving other issues aside, there's also a matter of familiarity.
If questions/problems arise in a build with an unknown PCB, members
wouldn't know if it's a build error, or perhaps an issue with the
pcb layout/schematics/circuit design or modification/any parts
choices/substitutions. Trying to answer questions about them often
requires more effort and knowledge.
The store boards (and the underlying designs) are known quantities
and many members have used them successfully. So more people
are likely to answer questions on builds with these boards based on
their own experience.
If questions/problems arise in a build with an unknown PCB, members
wouldn't know if it's a build error, or perhaps an issue with the
pcb layout/schematics/circuit design or modification/any parts
choices/substitutions. Trying to answer questions about them often
requires more effort and knowledge.
The store boards (and the underlying designs) are known quantities
and many members have used them successfully. So more people
are likely to answer questions on builds with these boards based on
their own experience.
There is obviously a lot of animosity against anyone who tries to profit from someone else's design.
As the P1.7 PCBs are not available it is not uncommon for us to source them from another source.
It might be better to ask for help against the schematic rather than alienate members by stating where you sourced the PCBs.
The P1.7 is a balanced pre-amplifier but it's easy enough to use it as an unbalanced unit.
The 4 gang pot can be a bit of a challenge.
As the P1.7 PCBs are not available it is not uncommon for us to source them from another source.
It might be better to ask for help against the schematic rather than alienate members by stating where you sourced the PCBs.
The P1.7 is a balanced pre-amplifier but it's easy enough to use it as an unbalanced unit.
The 4 gang pot can be a bit of a challenge.
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