GoodSoundClub - Romy the Cat's Audio Site

10-10-2010

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ArmAlex
Iran
Posts 106
Joined on 02-15-2009

Post #:	41
Post ID:	14692
Reply to:	5561

Will Mel. drive Gryphon

Romy, I plan to build Melquiades. But there are couple of questions:
1-One of speaker options is Gryphon Trident, it is an active bass speaker so Mel should drive MF & HF only. In your opinion can Mel drive
these speakers?
2-If yes then driving an active speaker Mel doesn't need to handle LF so what modification it needs to serve this purpose?

Regards, Armen

Romy the Cat wrote:
Here is a separate thread where any questions and answers regarding how to build Melquiades might be piled up.

10-10-2010

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Romy the Cat

Boston, MA
Posts 10,128
Joined on 05-28-2004

Post #:	42
Post ID:	14693
Reply to:	14692

I have no idea Gryphon Trident are but…

ArmAlex wrote:
Romy, I plan to build Melquiades. But there are couple of questions:
1-One of speaker options is Gryphon Trident, it is an active bass speaker so Mel should drive MF & HF only. In your opinion can Mel drive these speakers?

Armen, I have no idea. What does it mean drive? To power Gryphon’s MF & HF only in the room of your size and do not send stages into A2? Mostly likely it will. Will it sound as it could with higher sensitivity drivers? I do not know but I doubt.

ArmAlex wrote:
2-If yes then driving an active speaker Mel doesn't need to handle LF so what modification it needs to serve this purpose?

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

10-11-2010

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ArmAlex
Iran
Posts 106
Joined on 02-15-2009

Post #:	43
Post ID:	14698
Reply to:	14693

Melquiades for Trident

I you have an active speaker and want like to use Melquiades then you need a DSET configuration, Find out where and how your Gryphon rolls off MF and introduce the same filter from your DSET in the amp. Use much lower value of coupling capacitor and OPT with much less inductance to optimize the amp for HF operation.

Dear Romy, Crossover frequencies are 250 and 2Khz, would you please be more specific about changes that is needed?
As I'm not very technical and a friend is going to help me to build Melquides.

Many Thanks, Armen

02-22-2011

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Romy the Cat

Boston, MA
Posts 10,128
Joined on 05-28-2004

Post #:	45
Post ID:	15609
Reply to:	15608

The AMCC-160 core.

Yes, the AMCC-160 it was what I was able to get for reasonable price. When you be done then measure response at full power and publish the result.

The Cat

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

03-18-2011

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Dominik
Poland
Posts 48
Joined on 09-14-2008

Post #:	46
Post ID:	15796
Reply to:	15609

Tribute transformers and chokes

Today recive transformers and chokes from Pieter. I was prepare for size of OPT but not for size of PS chokes!!!!

There is no paint on parts on my request. Here are pics of most of the big parts,

tribute OPT.jpg

Now i must find a way how to put this all in two monoblock enclousure when I do this then will need some help from You guys to make this thing work...

Best

Dominik

03-19-2011

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Dominik
Poland
Posts 48
Joined on 09-14-2008

Post #:	48
Post ID:	15801
Reply to:	15799

Toroids from Poland

N-set,
The caps from pic is
C2 -2000uF
C10 -6000uF
Toroids transformer company comes from my city http://www.toroidy.pl/index.php?option=com_content&view=article&id=6&Itemid=7&lang=en.

Yes, I know that tube amps(all audio equipment) and kids its not good mix, That is the one of the reasons that I go to another place in 2 years, and will build dedicated room . For now she is to little to reach equipment Smile

03-19-2011

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Romy the Cat

Boston, MA
Posts 10,128
Joined on 05-28-2004

Post #:	50
Post ID:	15803
Reply to:	15802

Think about ergonomics and esthetics of your design.

It looks like you will be building not DSET but a full range amp. You need to come up with the chassis design and it is a bit complicated possess. Do not be in hurry with this possess. You need to think about the location of the main elements on chassis, about the shortening and striating of signal paths, about separation of signal passes and power passes, about grounding, heat dissipation, galvanic proximity and many many other things. In your case there is a complication: Pieter made your transformer attractive looking. This in many cases would lead people to make an amp chassis on a flat table with transformers, tube and caps sticking out of chassis like mushrooms. I personally do not like this design, purely on esthetics, even thought I agree that there are a lot of justifiable advantages in this flat panel anticlimactic design.

Sure, my personal taste in esthetics means nothing to you, and it is how it shall be, but I do encourage you to come with your own version of pleasant looking and smart design. I personally like what all elements of amp are hidden and transformers, chokes and caps are not exposed. But it is me…..

The Cat

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

03-19-2011

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N-set
Gdansk, Poland
Posts 616
Joined on 01-07-2006

Post #:	51
Post ID:	15804
Reply to:	15803

The geometry

This is what I try to stick to:
Try to create closed magnetic (steel) loops around magnetics. Ideally acompany it
with closed electric (copper) loops. This I think Pieter has done that already for you, but,
as Romy impicite suggests, double boxing will not hurt for sure.
The transformer and the rectifiers should be as close as possible: the rectifiers' switching
kaka can (and usually does)
excite the transformer secondary and polutes the area with RF. Keep it as far as possible
from the input stages. Think diagonal. The PS input choke sees a huge voltage swing, so there are strong
electric and magnetic fields around it. Isolate it well too. From both the trafo+rectifier and the signal path.
Distance is our friend, the dipole fileds die out with the distance squared.
Orient the cores of your magnetics 90deg wrt each other, this will supress the magnetic cross-talk.
Caps don't like heat (nor vibrations) and 6c33c is an open oven. Sorbothane O-rings between the input tube
sockets and the chassis and below the caps would not hurt.
The usual things: twisted pairs (keep the low resistance loops as small as possible),
star grounding, voltage regulators as close as doable to the regulated tubes, etc.
The excellent source to understand some of those things
is this:
"Grounding and Shielding Techniques"
Ralph Morrison

Goos meditative mood, a small shot of a prime Polish vodka and ample time to visualize
the things and play like with lego helps!
Bets luck,
N-set

Cheers,
Jarek
STACORE

03-20-2011

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Romy the Cat

Boston, MA
Posts 10,128
Joined on 05-28-2004

Post #:	52
Post ID:	15805
Reply to:	15804

The magnetics taking considerations.

N-set wrote:
This is what I try to stick to:
Try to create closed magnetic (steel) loops around magnetics. Ideally acompany it
with closed electric (copper) loops. This I think Pieter has done that already for you, but,
as Romy impicite suggests, double boxing will not hurt for sure.

Do not sign me to this ides and I did not “suggested” anything. The closed magnetic loops around magnetic is as good but it also a bit controversial. The torpids radiate a lot of “things” out of the center hole and there is a lot of slippery moments when you try to put a lot of magnetics, unparticular torpid, in a close space.

That would all depend from multiple factors and the biggest of them if the amp will be one chassis of two, In case of two chassis I would go for PS chassis made from other material then steel. If case of the single chassis the thing is more interesting. You would like to pack everything more compact and to have steel chassis but it might bite you for your tail. So, the thinks need to be well thought. If you look at the thread “Building Melquiades: Chronicle of full-range”:

http://www.goodsoundclub.com/Forums/ShowPost.aspx?postID=2502

…then you will see my idea: to have steel chassis with magnetiks outside of chassis and the signals inside of chassis. With torpid it would be much different of cause. I do not know why Dominik went fortorpid. Torpid has a lot of advantage but it also has a lot of disadvantages, of them that you can’t not flat mount a multiple powerful torpids to a the same steel surface as each of them will arouse different resonances in the same chassis surface and it might be tricky to make the chassis silent, unless one goes for very think mounting surface.

Again, there is nothing dramatic in it and all those things are very addressable. The amp’ chassis however need to be thought and design with considerations “magnetics taking”.

The Cat

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

03-20-2011

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N-set
Gdansk, Poland
Posts 616
Joined on 01-07-2006

Post #:	53
Post ID:	15806
Reply to:	15805

Magnetics and such

I think you did not understand what I mean. Also, there was a subtle word "implicite"
in my statement which makes a difference here.
Closed magnetic loops: I did not mean the cores of magnetics, but the
geometry of the shields. To catch the magnetic flux
escaping the core and constraint it, a closed loop around the
shielded element is needed. Magnetic field is source-less. In propagates in closed
loops. A box, shielding from all directions (4pi solid angle) is great. If there is no chance for a box,
make at least a loop. Why your SU-2 are multiple boxed? Because shields
also saturate, just like cores, and loose efficiency. So double boxing both sensitive and
strongly poluting elements is a good idea. In this case it would be
putting potted elements in one more boxes and signals OUTSIDE those boxe.
I see absolutely no controversy here.
This is a standard knowledge and practice. Steel is not the only material of course,
one can use aluminium but it saturates much faster so it must be much thicker.

Toroids: I've never used them too much, but one of the standard facts is that such cores
emit much less than other types, esp. EI.

Cheers,
Jarek
STACORE

03-20-2011

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Romy the Cat

Boston, MA
Posts 10,128
Joined on 05-28-2004

Post #:	54
Post ID:	15807
Reply to:	15806

I was taling about purely mechanical noises...

Actually my SU-2 has multiple shields for different reasons – they are different type of shields and each of them work most effectively under different conditions and help for different type external noise. However, it is not really important. What you are saying has to do with shielding. It is important point but it was absolutely not what I meant. I was not taking about shielding but about the way how chassis react to stay field radiated from transmitters and chokes. If you have an average or beyond average chassis thickness and you put on one of the panel of this chassis 5-6 powerful transformer and chokes then you will have a lot of resonances coming from the fact that stay fields will use the chassis as core. It is very had to comfort this type of resonances. It has nothing to do with shielding but with purely mechanical noises that chassis will pickup from magnetics.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

03-20-2011

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N-set
Gdansk, Poland
Posts 616
Joined on 01-07-2006

Post #:	55
Post ID:	15808
Reply to:	15807

Vibration controll...

...is a pita, no, no, PITA! In my circumstances I've had so far
reasonable results using foamed natural rubber to mechanicaly
damp the chassis. Has anyone tried that ridiculously expensive
silicone gel tape/chips?

As for the multiple shields on MC's. High perm materias shield the best (better confine
the stray flux) but they saturate fast, so they have to be shielded too. I'd guess
a +/- standard chain of shields is something like that: mumetal inside, then permalloy (50% Ni)
then soft steel, thick or twice. And Cu electrical shield somewhere there too.
Steels magnetically shields permalloy, permalloy mumetal, mumetal
the cores, and Cu takes care of electric fields.

Cheers,
Jarek
STACORE

03-20-2011

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Romy the Cat

Boston, MA
Posts 10,128
Joined on 05-28-2004

Post #:	56
Post ID:	15809
Reply to:	15808

Use non-ferromagnetic materials to mount magnetics

For vibration control coming from multiple powerful indictors I feel there is nothing better then the “wing strategy” that invented for 6-ch Melquiades. Sine I have all transforms and chokes in toroid shape I put them on L-brackets and lifted them up from chassis. This made the PS to look like a forest but it made chassis more or less silent. If I would like to take it further then I might turn the “wings” and minimize the magnetics cross talk. If I do it from start then I would do PS chassis from aluminum. If it was one chassis amp then I would use steel and I would go for the panel that host magnetic made mad from 3/4 steel. The best way to I think for one chassis is to have steel enclosure but the panel with transforms and chokes to me made from ½ aluminum sheet. Again, it needs to be though before one order chassis. The rubber decouples and soft bold do not work too well in my observation.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

03-20-2011

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Dominik
Poland
Posts 48
Joined on 09-14-2008

Post #:	57
Post ID:	15810
Reply to:	15809

Enclousure project

When I decided to build this amp I know from the start that it will look not as 99% of amps. I do not like when transformers are visible.My wife hate this "mushroms" looks.

When I speaking with Pieter i told him to not poting chokes and transformers. He want to poting for couple reasons, so I say yes but also told him to not give to much work with looks (paint etc) .

I spend all sunday on thinking how to build the thing... It is first time so its not easy.

I took Roomy tips:

1) Keep point “M” as close to R2 as possible.
2) Keep point “L” as close to R18 as possible.
3) Keep C10 as close to OTP as possible.
4) Keep R4 and R6 as close to grid as possible.
5) Keep R5 close to grid as possible.
6) Bring the C4 and C5 ground leads right to the gas tubes sockets.
7) Keep the gas tube very close to the first stage’s grid
8) Keep filament supplies far for the signal paths
9) Keep OPT as close as possible to the V4
10) Keep V3 and V4 as close as possible.
11) Keep V4 with an island where no parts will be closer to the tube socket then a reasonable temperature permitted distance.

My room give my two options,

1. narow but high amp

2. separate PS and short amp audio table.jpg

If option one then it could look something like this: amp proiect.jpg

Toroids sit on first floor. it could by vertical or horizontal position of transformers.

On second floor there are the chokes, next floor is OPT and big caps. Position of caps and lamps can by red or blue(to shorten way to chokes if it is nessesary).

What do You thing?

Best

Dominik

04-19-2011

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Tax

Sydney, Australia
Posts 17
Joined on 04-11-2011

Post #:	59
Post ID:	16107
Reply to:	6480

Melquiades Schematic Version 4.4 ...where is R7 and R8?

Tax wrote:
"Sorry to ask, but where is R7 & R8 on version 4.4 of the attached schematic, is it a deliberate puzzle to test the Moron or a numbering error?"

The CaT wrote:

"It looks like R7 and R8 are not there. They use to be filter resisters for my DSET version and I did not put them on. I did not bother to rename the rest resistors. BTW, if you posted the very same question at the forum then others would also learn that R7 and R8 are missing. My objective is that somebody who would have interest in Milq to use the forum old post as knowledge base."

So for any other interested Melq builders; Please note that the lack of R7 & R8 resistors in the schematic version 4.4 is due to a numbering error. So continue with the numbering for the rest of the resistors.

	Target	Threads for related reading	Most recent post in related threads	Forum	Replies	Views	Started
»	New	Full range Melquiades implementation..	Solved...	Melquiades Amplifier Forum	81	560257	02-23-2011
»	New	Melquiades For Dummies™ - step by step...	Amp still open...	Melquiades Amplifier Forum	28	212098	08-29-2007
»	New	Building Melquiades: Chronicle of full-range..	VR2 issue leading to jump in current on 6C33 tube...	Melquiades Amplifier Forum	44	430601	06-09-2006

	Target	Threads for related reading	Most recent post in related threads	Forum	Replies	Views	Started
»	New	Full range Melquiades implementation..	Solved...	Melquiades Amplifier Forum	81	560257	02-23-2011
»	New	Melquiades For Dummies™ - step by step...	Amp still open...	Melquiades Amplifier Forum	28	212098	08-29-2007
»	New	Building Melquiades: Chronicle of full-range..	VR2 issue leading to jump in current on 6C33 tube...	Melquiades Amplifier Forum	44	430601	06-09-2006