Search found 72 matches

by Gerry
Sun Mar 18, 2018 9:42 pm
Forum: Valves
Topic: Rose RV-23 preamp valves. $xECC82, or 2xECC82 + 2xECC83?
Replies: 5
Views: 7866

Re: Rose RV-23 preamp valves. $xECC82, or 2xECC82 + 2xECC83?

Long time Adrian..... But
Is it a RV23SE or a plain RV23? The RV23SE has a separate PSU (transformer) . If so 4x ecc81, if not it is the the mix. Sean messed around a bit with valves in various models. I have some paperwork/old emails from him.
by Gerry
Mon May 16, 2016 7:14 pm
Forum: Beginners
Topic: Preamp o/p cap values.....confussed
Replies: 3
Views: 4982

Re: Preamp o/p cap values.....confussed

IP

Thanks.
It is a preamp.
I swapped out the original for PIO (2.0) with Teflon (0.1)bypass.
The added another 2.0 (PIO) as I had one following comments and the calculator, trying get as much bandwidth as possible.
by Gerry
Mon May 16, 2016 11:16 am
Forum: Beginners
Topic: Preamp o/p cap values.....confussed
Replies: 3
Views: 4982

Preamp o/p cap values.....confussed

Hi all Been a while.... A little confused on pre-amp out cap values. I have a ARC LS7 (circuit schematic) which has 2.0uf o/p cap bypassed with 0.01uf. (stock) The power-amp has an input Independence of 150Kohms (unbalance) and 100Kohms (balanced). I use it unbalanced. Reading an old thread on Pinkf...
by Gerry
Tue Jan 25, 2011 7:23 pm
Forum: Assorted Stuff
Topic: BT telephone poles.
Replies: 47
Views: 16390

Yes, my pole feed two other houses. I understand they don't backdate wayleave payments, which is a pity cos the pole has been "mine" for 20 years. :wink: I'm not sure that is necessarily true. They will tell you lots of things to stop paying. The original way-leave agreement will have the...
by Gerry
Tue Nov 09, 2010 7:22 pm
Forum: General Vinyl
Topic: phono load resistors
Replies: 36
Views: 20886

Graeme

Not sure if you've found the Hagerman site which has a calculator which provides the parallel value dependent on the phono stage and turns ratio.
HERE
by Gerry
Sun Nov 07, 2010 6:31 pm
Forum: General Vinyl
Topic: phono load resistors
Replies: 36
Views: 20886

Graeme Yes I'm using 1Meg in place of the 47K and loading on the primary. The reason as I understand it is the 1meg ties the grid to the ground, in effect it negates the secondary loading. There was a lot on this on the old forum HERE . Andrew was the first to really play with it and demonstrate it ...
by Gerry
Tue Oct 05, 2010 10:14 am
Forum: General Vinyl
Topic: Cartridge Loading and method
Replies: 8
Views: 7611

Why then when measuring do you not get a reading of 40R? By measuring do you mean with a ohmmeter? If so all you will see is the DC resistance of the transformer primary in parallel with the resistor. The values we are talking about with the transformed resistances are actually impedances, so valid...
by Gerry
Tue Oct 05, 2010 8:58 am
Forum: General Vinyl
Topic: Cartridge Loading and method
Replies: 8
Views: 7611

Thanks guys, though still a little confused. The fact we replaced the 47K with 1Meg, to my understanding, meant that the loading resistor on the primary was the value required. So if you wanted 40R, a 40R resistor was put in parallel across the input? Why then when measuring do you not get a reading...
by Gerry
Mon Oct 04, 2010 7:12 pm
Forum: General Vinyl
Topic: Cartridge Loading and method
Replies: 8
Views: 7611

Cartridge Loading and method

This harks back to Andrew's work suggestions at Witham all those years ago and primary vs secondary loading. The topic has come up elsewhere and I thought I had it all sorted in my mind but I'm beginning to questions myself. The idea was when loading on the primary, the 47K in the phonostage was rep...
by Gerry
Sun Dec 20, 2009 7:03 pm
Forum: Assorted Stuff
Topic: Two for the price of one...
Replies: 16
Views: 7845

They did it!!! :lol: :lol: :lol:

Or is that ....we?
by Gerry
Thu Dec 10, 2009 8:38 am
Forum: Assorted Stuff
Topic: It can happen here; again!
Replies: 2
Views: 2613

Andrew This problem is increasing. The real difficultly is ebay as they do not believe they are an auction house as your contract is with them, they have moved to Luxembourg to escape various EU regulations. They will claim they are a facilitator, not auction. But you place a bid!!! Under the sale o...
by Gerry
Thu Nov 12, 2009 10:10 pm
Forum: Assorted Stuff
Topic: Question....probably stupid...!
Replies: 31
Views: 16193

Ed
Thanks. I want to run them at 50-52ma ideally with the HT at 470v. I don't want to crank them too much, just not worth it.
Problem is getting to the board in this amp...along with the 36kg it weighs!
by Gerry
Thu Nov 12, 2009 7:19 pm
Forum: Assorted Stuff
Topic: Question....probably stupid...!
Replies: 31
Views: 16193

Interesting what you say Nick. They are supposed to be (according to the instructions/manual) totally interchangeable, but I am beginning to wonder. I can understand replacing EL34s with KT88s and a problem, the heater current draw is that much more for a start. 6550/KT88 are very similar on the hea...
by Gerry
Thu Nov 12, 2009 5:46 pm
Forum: Assorted Stuff
Topic: Question....probably stupid...!
Replies: 31
Views: 16193

if the max neg bias you can give the kt88s is giving 100+ma then the answer has got to be yes Sorry Ed maybe I wasn't clear. I've not measured the KT88 at 106...this is from the matching. (If that makes sense). So I assume they are a strong valve which will draw 106ma??? The plate heats up so quick...
by Gerry
Thu Nov 12, 2009 5:00 pm
Forum: Assorted Stuff
Topic: Question....probably stupid...!
Replies: 31
Views: 16193

Following on from this....I did get 8 new Gold Lion KT88s, however I am really struggling to get them biased correctly. They were all matched, however the previous 6550 were 76/77ma as matched and the KT88s are 106ma. Could it be that the bias circuit resistors are going to need changing....these va...