Author Topic: Deacy Amp (?)  (Read 39582 times)

Ivana

Re: Deacy Amp (?)
« Reply #40 on: October 26, 2005, 03:32:21 PM »
I think that "3.5:1+1" is not Rp and Rs are DC resistances but a relation ("/" :)))) of the... coils? spirals?...  :icon_redface: my bad english...

R.G.

Re: Deacy Amp (?)
« Reply #41 on: October 26, 2005, 08:22:06 PM »
The "3.1+3.1:1" is the voltage (and turns) ratio of the windings. If you put 1V on the "1" winding, then 3.1V will appear on each of the other two.

The Rp and Rs numbers are indeed the DC resistance of the copper in the windings. This has little to do with the turns ratio or impedance ratio.

The impedance ratios are yet another way of describing the same transformer, and possibly more useful. They describe what impedance appears at the primary winding if the specified loading is applied at the secondary. That is, the "1.2Kct to 3.2ohm" specification promises you that if you put a 3.2 ohm resistor on the secondary, then whatever drives the primary will think it's a 1.2K ohm load.

The turns ratio and impedance ratios are related. The impedance ratio is the square of the turns ratio. So in the case of a 3.1+3.1:1 transformer (voltage) you'd have a
(3.1+3.1)squared to 1 impedance or 38:1 impedance ratio. If the load is 3.2 ohms, then the primary load is  121.8 ohms.

The real "doesn't make sense" in this case is that the voltage ratios and the impedance ratios don't relate by the squared function.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

christiancm

Re: Deacy Amp (?)
« Reply #42 on: December 03, 2005, 01:42:21 AM »
Hello everybody,

OK Ivana, it's very  interesting but what is the impedance values of the OC81D and voltage or impedance values for the T1 along with power ratings for both transformers ?

Ivana

Re: Deacy Amp (?)
« Reply #43 on: December 03, 2005, 03:47:08 AM »
I think that "impedance values of the OC81D" is not exist as a parameter. It is not a pentode. The main aim is to preserve the power overloading of the transistor.

rotylee

Re: Deacy Amp (?)
« Reply #44 on: August 03, 2013, 09:10:05 AM »

Kipper4

Re: Deacy Amp (?)
« Reply #45 on: August 03, 2013, 10:01:00 AM »
Also check out knight audio technologies Deacy amp. This is the kit I bought and was my first DIY project last Christmas and I haven't stopped learning since
"Duck_Arse
otherwise, you might end-up with SOIC or gullwings, for surface mounts."


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rotylee

Re: Deacy Amp (?)
« Reply #46 on: August 03, 2013, 07:25:03 PM »
Kipper4 :
did you get the trannies there.? they seem a little steep. 
are they different what most are using for this kinda app.
>>>
WARNING! There are a number of third party transformers for sale on the internet. Some are configured incorrectly with the primary coils of the interstage transformer reverse-wound. In this instance, the amplifier will not work correctly untill you swap over the primary connections. A number of these transformers, and some claim to have been tested in the actual Deacy circuit, are also of the wrong turns ratios, which, causes too much gain within the amplifier stages.
>>>
an ok deal on PCB and components  though.
are they geranium transistors?



 

Kipper4

Re: Deacy Amp (?)
« Reply #47 on: August 04, 2013, 02:50:37 AM »
No i did not use the transformers sold by KAT. Yes they are a little steep but i wish i had used them now.
I used some bought from ebay in eastern europe.
Any yes they are configured differantly i had to swap 2 legs over on the transformers.
it sounds good but i think it could do better with better qaulity built transormers. IMO.
"Duck_Arse
otherwise, you might end-up with SOIC or gullwings, for surface mounts."


Smoke me a Kipper. I'll be back for breakfast.

Grey Paper.
http://www.aronnelson.com/DIYFiles/up/

greaser_au

Re: Deacy Amp (?)
« Reply #48 on: August 04, 2013, 03:40:39 AM »
No i did not use the transformers sold by KAT. Yes they are a little steep but i wish i had used them now.
I used some bought from ebay in eastern europe.
Any yes they are configured differantly i had to swap 2 legs over on the transformers.
it sounds good but i think it could do better with better qaulity built transormers. IMO.

Rich,

just out of interest:  what did you use for a speaker/cabinet?

david

Kipper4

Re: Deacy Amp (?)
« Reply #49 on: August 04, 2013, 02:24:07 PM »
I had an old hifi (6" speaker and 2" tweeter) in the loft from an old 8 track my wifes father passed onto us.
I used it because i wanted that small speaker thing that mr May did with his.
I took the back off and put the circuits inside and screwed it back on.
I say circuits because i also built the KAT direct record/headphones circuit and an integrated treble booster.
The treble booster was an old supposedly brian may treble booster traced one unfortunately its ground positive so i have it supplied by a battery that clips on the back of the cab.
i put plugs to go in and out of the treble booster and an amp direct jack too and use a short patch cable on the back to put the treble booster in line.
A friend did a simultanious build and used a single wallwart power supply for both amp and treble booster but used a max1044 i think it was to reverse the grounds for his treble booster but he had a lot of problems with it before he did a similar thing to me and gave them there own power supplys as they didnt want to play well together as he had them.
I also have the possibilty to use a pp9 battery supply for the amp (lead sticking out the back of the amp) Should i ever decide to take up busking.
:)
"Duck_Arse
otherwise, you might end-up with SOIC or gullwings, for surface mounts."


Smoke me a Kipper. I'll be back for breakfast.

Grey Paper.
http://www.aronnelson.com/DIYFiles/up/

Re: Deacy Amp (?)
« Reply #50 on: January 06, 2016, 04:06:04 PM »
The Fryer Sound Deacy Amp sounds really amazing and it is so close to the sound of a good tube amp.
Check out my demo here:
https://www.youtube.com/watch?v=PnNJfHTxliw

Kipper4

Re: Deacy Amp (?)
« Reply #51 on: January 06, 2016, 06:43:02 PM »
Nice sound. I wish you had played with the guitar volume though.
I guess your not using a treble booster since you say no effects then?
Those pups sure sound good too.
Sweet
Rich
"Duck_Arse
otherwise, you might end-up with SOIC or gullwings, for surface mounts."


Smoke me a Kipper. I'll be back for breakfast.

Grey Paper.
http://www.aronnelson.com/DIYFiles/up/

Re: Deacy Amp (?)
« Reply #52 on: January 11, 2016, 03:25:37 PM »
Thanks, see the second part from Clean to Overdrive by just rolling up the volume guitar pot below (there is no treble booster):
https://www.youtube.com/watch?v=CjHgcS4tPqQ

Kipper4

Re: Deacy Amp (?)
« Reply #53 on: January 11, 2016, 03:27:51 PM »
Did you get the fryer transformers in there too?
"Duck_Arse
otherwise, you might end-up with SOIC or gullwings, for surface mounts."


Smoke me a Kipper. I'll be back for breakfast.

Grey Paper.
http://www.aronnelson.com/DIYFiles/up/

Re: Deacy Amp (?)
« Reply #54 on: January 11, 2016, 03:58:29 PM »
Yes there are two Fryer transformers in the circuit.

Re: Deacy Amp (?)
« Reply #55 on: January 24, 2016, 03:28:18 PM »
Sorry for the broken links, please find my demos of the Fryer Sound Deacy Amp here:
https://www.youtube.com/watch?v=zQ5xuR0N_fo
https://www.youtube.com/watch?v=o8VL64gORKw

Rob_Lo

Re: Deacy Amp (?)
« Reply #56 on: October 03, 2016, 05:03:54 PM »
Hi,

I am looking into building a Deacy replica from Paul Stevensons stripboard layout.

https://paulinthelab.blogspot.com/2012/06/brian-may-deacy-amplifier-stripboard.html?m=1

He states this is based off of Greg Fryers design...but wasn't Fryer the one who developed the KAT build along with Nigel? Because this layout is much different than the KAT schematics (which looks similar to the original mullard layout). Either way there seems to be much misdirection and misinformation surrounding the legend.

I didn't want to use the Eagle transformers because their output seems a but low. And I have i ohm drivers lying around so I settled on the Xicon trannies from Mouser..which are still significantly lower output than the 1w specified

http://www.mouser.com/Search/m_ProductDetail.aspx?Xicon%2F42TU048-RC%2F&qs=LQJGOuQCHKR6gBOQxy1apw%3D%3D

http://www.mouser.com/Search/m_ProductDetail.aspx?Xicon%2F42TM024-RC%2F&qs=%252bLh6ltJumVS5xwocZBTZJg%3D%3D

My question (forgive me I'm green and still learning)....does the topology of the layout have to change? Or are trannies with similar specs interchangeable




nickbungus

Re: Deacy Amp (?)
« Reply #57 on: October 04, 2016, 08:11:42 AM »
Hi.  Could you please share the links for the Mullard and the KAT?
To the extreme, I rock a mic like a vandal.
Light up a stage and wax a chump like a candle.

greaser_au

Re: Deacy Amp (?)
« Reply #58 on: October 04, 2016, 07:01:52 PM »
Hi.  Could you please share the links for the Mullard and the KAT?

Knight Audio : http://www.deacyamp.com/    have a look under the 'Project room' for the Deacy-style amp stuff, there's a few downloads... The amplifier kits and transformers seem to have disappeared from the shop pages though, so possibly they might not sell them any more... :(

david


*edited for clarity
« Last Edit: October 04, 2016, 11:38:33 PM by greaser_au »

digi2t

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Re: Deacy Amp (?)
« Reply #59 on: October 04, 2016, 08:27:38 PM »
FWIW... I built mine with the transistor set from Ebay, and the Eagle transformer set from Ebay. Actually only used the first two transistors from the Ebay set (AC125 / AC126), opting for a matched pair of AC128K's that I had on hand for Q3/4. Used the schematic from the Vox Deacy, along with a Fryer boost on the front end.



http://www.diystompboxes.com/smfforum/index.php?topic=105657.0



I had to build  +/- power supply onto the board to deal with the NPN/PNP deal, but no big deal. The most important element after the circuit is the speaker. I tried three different 8" whizzer cone speakers, and I found that the cheapest paper cone you can possibly find, is the best. Paper throughout works best. I tried one with foam edging, and it was totally wrong. It just doesn't project the midrange frequencies properly.

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