audio-talk

ed wrote: Fri Feb 03, 2023 2:43 pm

Nick wrote: Fri Feb 03, 2023 1:18 pm No, not certain. What is the current circuit?

I don't know. I have old circuits for AP10, AP30,AP70,A60,A70. I'm not sure of the provenance of any of them, it was a long time ago.
Perhaps Steve or Stu could comment on the ltp on their boards.

Yes there definitely is a LTP.

Thanks Nick

NVA famously don't have input coupling caps but mine do as removed them from my source components . I have red wima mks2 3.3uf in currently for input coupling not sure they are available in 47uf.

My film caps are evox rifa mmk 47uf 63v and bloody massive. I might look for wima and if ...

Good evening,

Been thinking about feedback caps in solid state power amplifiers. I only have experience of Naim, Avondale and NVA amplifiers. The feedback arrangement is similar in all of them. I know they have to be a certain value ie 47uf and above. Naim used a polarised electrolytic. Avondale ...

Yes it is a clone of the stage line.

I've got about 8 phono stages including the nva , personally I prefer the naim over the nva
.
.you can buy regulators for it , but I just use two 350va transformers ,2 33,000uf caps per rail and 1 bridge


Fair enough. Must be bigger than Coke cans those ...

DQ - is your phono stage based on the Naim Stageline or similar. They use two +24V rails as standard. Naim put the regs in the power supply at the end of one metre of wire. I would suggest that the regulator would be better close to the load if you were going to do it.

The NVA phono stage comes as standard with regulators. They are very simple . LM317 & 337 with the necessary resistors and 0.1uf film caps on input and output ( from memory).

I remember RD saying that the stage did benefit from regulators but very simple ones.

I am trying something which is quite ...

I suppose this would work with two secondaries that are not centre tapped ?

Many thanks. Will be doing it in the next few weeks hopefully.

Stu

As always the first place to start is with the documentation of the part:

In general, the best type of capacitors to use is solid tantalum. Solid tantalum capacitors have low impedance
even at high frequencies. Depending upon capacitor construction, it takes about 25 μF in aluminum electrolytic ...

There was some talk on pfm that using two positive regulators with LM317 in this way can be better than using the LM337 because the 317 regulates better. I wouldn't know about that.

The nva phono uses 317 and 337 in the traditional way. It has small film caps on the output of the regs which I ...

Two entirely separate transformer secondaries to their own bridge rectifier and cap. Positive on cap to vin on regulator. Negative on cap to 0v. That then gives you two entirely separate 18v supplies call them a and b. Connect vout of supply b to 0v of supply a. Vout of supply a is +18v. Point ...

Hello. Trying to get my little brain round something and need a little help.

I have four Avondale Audio TPR4 regulators sitting around doing nowt. There are two separate positive voltage regulators on each board. Its basically a tracking pre regulator with voltage reference and capacitance ...

Cressy Snr wrote: Sun Nov 13, 2022 4:30 pm

Ray P wrote: Sun Nov 13, 2022 3:31 pm It doesn't look as though you're using the feet that were in the box I gave you - the speakers were much more stable when fitted.

That job is on the list for next week. I need to get some shorter M6 bolts than the ones I have.

Hacksaw

Cressy Snr wrote: Sun Nov 06, 2022 10:08 pm NVA based SS amp is now a permanent fixture:
2891FE90-764B-4323-88E4-480681E83264.jpeg
With 85dB efficient speakers, a solid-state amp of decent power is the obvious choice.

Looks easy on the eye Steve. I expect it's kind to the ears too.

I must agree with something Paul B said earlier.

At Owston in the past, at least half of the music played is not to my taste at all, and makes evaluating the kit a problem.

Before anyone else says, I dare say what I do like is not to everyone's taste either. :lol:


I certainly concur there ...