GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Melquiades Amplifier
In the Thread: My Koshka is meowing

Post Subject: Two tier topologyPosted by Tax on: 3/1/2015

Thanks Romy!
I went with two tiers as I do not have much space between the speakers and the side walls as I have a 2.5M cabinet on the front wall.
I named my amp Koshka as I always felt Koshka made a contribution to the development of the Melquiades and the mood of the owner 😆
Is there a way I can upload multiple photos so I can share some photos from various stages of the build?
Yes, both boards (tiers) are suspended by small rubber loops and hooks so anti vibration is built in. The boards are 26mm thick. The transformers and other bits are screwed into the board. Very good vibration absorption.
The OPT and valves sit on the top board which is also suspended. I am also putting castors on the chassis so I can roll it out of the room to work on when I want to change something. I have had to do some tweaking to the circuit by adding some vcap and mundorf film caps I had on hand. Could be because of the length of ps cable causing inductance or electrolytic caps being new, I was getting a bit of sibilance and a hardness in a particular register. The bypass caps seem to have smoothened this out.I am finally beginning to appreciate "dynamic viscosity" and now understand what you have been describing.
Nothing is visible over the top of the chassis as the OPT and valves sit inside. The front cutout serves two purposes, 1 allows me to see the 6C33C glow. 2 allows ventilation for natural cooling.I hope to get the finished chassis back from the cabinet maker by next weekend.
There is a stainless steel plate fixed to the underside of the amplifier board as extra precaution to isolate it from power supply hysteresis.
I have enough space on both boards if I need to go DSET or 3 Channel so it is a bit future proof. With the Avantgarde speakers I do notneed DSET as the subwoofer has its own plate amp.

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