Nick G modified Lentek Head Amp

Hi Jez,

The ZTX’s maintain decent Hfe in the circuit with standard values with a quiescent current in the region of 250 microamps so they are a good choice for this circuit electrically. I have used these devices since they were first introduced because of their linear Hfe characteristics. I cannot comment on sound quality in the Lentek circuit until I have some listening time under my belt probably around springtime. Although if I get chance to sneak into the workshop over Xmas I may do a quick hardwire job for a first impression as the low component count makes this easy enough.

Incidentally Jez, I was not considering offering boards or modules using this circuit when I said I would get some boards made. This is purely to make life easy for component comparisons as a fun personal project in the spirit of the forum ethos and I am happy to disclose any interesting findings as the project progresses.

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Originally Posted by Paul Hynes

Hi Jez,

The ZTX’s maintain decent Hfe in the circuit with standard values with a quiescent current in the region of 250 microamps so they are a good choice for this circuit electrically. I have used these devices since they were first introduced because of their linear Hfe characteristics. I cannot comment on sound quality in the Lentek circuit until I have some listening time under my belt probably around springtime. Although if I get chance to sneak into the workshop over Xmas I may do a quick hardwire job for a first impression as the low component count makes this easy enough.

Incidentally Jez, I was not considering offering boards or modules using this circuit when I said I would get some boards made. This is purely to make life easy for component comparisons as a fun personal project in the spirit of the forum ethos and I am happy to disclose any interesting findings as the project progresses.

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Same here... useful devices for a wide range of applications.. I remember when they were Ferranti... and it were all trees round here you know :wheniwasaboy: :)

I have no issues if you had been planning to offer boards... the designs in the public domain :) My offer to do so earlier in the thread is merely me thinking maybe I can make a wee bit of money here and there from it if there is more demand for Lentek head amps than available ones.... If, as I suspect, people won't pay more for a new one than for a second hand one (nowt as queer as folk..) it will go nowhere...

I have my very low noise test gear on the bench ATM anyway as I'm building one of my FET head amps (up market one, not the budget one) for a customer, so I will probably knock up a Lentek this end as well... and knowing me it will end up a "souped up" one...

I also chose Transistors from the ZTX range, to use in a low voltage, low noise, temperature compensating, voltage refrence, for the Soul series, good devices.:)
Good luck with the developement/testing Paul, Jez.

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Originally Posted by Paul Hynes

Hi Jez,

The ZTX’s maintain decent Hfe in the circuit with standard values with a quiescent current in the region of 250 microamps so they are a good choice for this circuit electrically. I have used these devices since they were first introduced because of their linear Hfe characteristics. I cannot comment on sound quality in the Lentek circuit until I have some listening time under my belt probably around springtime. Although if I get chance to sneak into the workshop over Xmas I may do a quick hardwire job for a first impression as the low component count makes this easy enough.

Incidentally Jez, I was not considering offering boards or modules using this circuit when I said I would get some boards made. This is purely to make life easy for component comparisons as a fun personal project in the spirit of the forum ethos and I am happy to disclose any interesting findings as the project progresses.

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Any further development on this? I'm using my Lentek (Nick G modded) to very good effect, it's the new year so I fancy something trying something different.

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Originally Posted by REXTON

Any further development on this? I'm using my Lentek (Nick G modded) to very good effect, it's the new year so I fancy something trying something different.

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I didn't get round to it and have been to busy with more important stuff TBH... I can't see me ever taking it further now the mental impetus has been lost. I doubt anyone would spend say £300 - £400 on a hugely souped up version of the Lentek anyway...

I would, if it was good! :)

Marco.

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Originally Posted by Arkless Electronics

I didn't get round to it and have been to busy with more important stuff TBH... I can't see me ever taking it further now the mental impetus has been lost. I doubt anyone would spend say £300 - £400 on a hugely souped up version of the Lentek anyway...

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why dont you tell us what you'd do to the Lentek and then lets US decide if we want to spend £3-400 of our money. You shouldn't make assumptions. ;)

I'm looking into getting mine further modded. Just looking at components and speaking to my favourite cable maker to see if something can be rustled up. What this space. :eek:

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Originally Posted by REXTON

why dont you tell us what you'd do to the Lentek and then lets US decide if we want to spend £3-400 of our money. You shouldn't make assumptions. ;)

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No. That's not how I do things. Any customer with the technical knowledge to know how any mods I make will be likely to effect things could design it themselves anyway... Those without that knowledge are in no position to comment anyway...
What I was proposing was NOT to take in Lenteks and modify them but to build new "Lentek's" from scratch in a much bigger case, which would be required for the mods I had in mind.
I can make one's of my own design that are much better anyway. As recent reviews show.

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Originally Posted by Arkless Electronics

No. That's not how I do things. Any customer with the technical knowledge to know how any mods I make will be likely to effect things could design it themselves anyway...
I can make one's of my own design that are much better anyway. As recent reviews show.

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Probably not the best way to handle customers Jez in that some of use like an active role in design and parts selection. I'm sure you can a much better head amp but I've not heard it so can't judge, the Lentek is a known entity and therefore worthy of investment unlike yours which is something that I'd have to spend £700+ on before I even had chance to hear it. A single review dosen't make a product. Anyway I'm already on with this project. Good luck with your future sales.