Potential Other Group Buys related to EUVLs F5X

[heinz1]

Hi,

I open this thread in order to discuss potential other group buy activities primarily intended but not limited to buyers of the F5X case and the PCBs specially designed for this case. It should be open also for the buyers of the F5X amplifier PCBs from the diy-audio store.

This thread should:

- indicate whether there there might be a group buy interest with regard to a specific component

- identify such components

- identify volonteers who are willing to organize the group buy

Group buys might be useful for the acquisition of these components (in parantheses: primary motivation for group buy)

- power supply transformers (identification of manufacturers in addition to Canadian SumR in Europe/Asia)

- regulator MOSFETs (matching involved)

- power supply capacitors (possible huge discounts)

- rectifier diodes (possible huge discounts)

Anything else I forgot?

[pmchoong]

Can we start with the Transformer GB?

[CanAm Man]

I'd support a transformer group buy (pending an idea of pricing/shipping)

[heinz1]

There was already some discussion on a possible transformer GB in the main thread starting with post #172:

F5X -- the EUVL Approach

Toroidy in Poland was mentioned as a possible manufacturer in Europe, as well as Canterbury Windings in the UK. I am unaware of manufacturers in Australia/Asia.

Due to high shipping costs, it is probably not practical to order from a single manufacturer.

Here are links to the homepages of the suppliers:

SumR: SumR - Richard Sumner Technology

Toroidy: TOROIDY.PL Transformatory Toroidalne Producent, Audio, Separacyjne, Trójfazowe, 230/110V, 110/230V, Na zamówienie

Canterbury Windings: Canterbury Windings Home

Anyway, I would be willing do to some organizational work in this GB, too.

[qusp]

i'd be interested in the toroids depending on timing, from sumR that is.

caps will depend, as i'm not in the case gb fairly specifically for reasons like this, as i will want to use rifa peh169 or similar and some larger unlytic type pp film shunt caps. i'm sorted for power relays for the foreseeable future, but you might want to band together for pricing on those.

titanium mounting bolts from the boltdepot which is utterly fantastic for fasteners of all kinds, great pricing and great range of bolts, washers, nuts etc and all come in different anodized colours and both imperial and metric. the flush-mount washers and matching countersunk head blts are perfect for fets and can be colour coded for easy identification of rail etc. more useful for amps with more outputs than the f5x

momentary switches could be another one. even hookup wire, contact me offline for that, i have a good line on bulk neotech upocc 16awg solid core in teflon if we can get the minimum order covered.

diodes perhaps, need to see the boms before we can make any more useful suggestions probably.

probably signal resistors too, prp for example you can buy direct from and get decent discounts, but takes a little while so we would want to get organized. on that note, the wire is about the only thing and perhaps bolts that i would maybe be able to help out with organizing. having just done a chunk of matching and running a sink gb, i'm not really up for anything that needs lots of work other than ordering and posting.

[alazira]

Antek does not have a shielded 500VA 2x15V, but their non-shielded 500VA 4x15 one is within the size parameters. If there is sufficient interest, perhaps they can be persuaded to add an "AS-5215" to their product offerings. Price would likely be about $60/Tx and $11 shipping for two transformers.

[samoloko]

I am for Toroidy as europian

[mravinsky]

The same as Samoloko

[heinz1]

Originally Posted by qusp

i'd be interested in the toroids depending on timing, from sumR that is.
....

Thanks very much, qusp, for your thoughts, reflections and your offer to help presumably in several aspects. Let's summarize. Other parts suitable for group buys are:

- mounting bolts
- switches
- hookup wire (I will send you a PM concerning this)
- (PRP) resistors

I have identified another item which is difficult to obtain and used in the EUVL case: Fischer SK 88-125 heatsinks used for the regulator MOSFETs and for the rectifier diodes.

Patrick mentions them here:

So far, I have only found the SK 88-100 (100 mm length), available from Buerklin.

I have not yet found the 125 mm variant. Here is the datasheet for the SK 88 series.

Prices from this vendor for the SK 88-100: 1-9 € 10,00/piece; 10-49: €8,51/piece; 50-99: €7,50/piece; 100 and up: €6,72 (19% VAT included)

This heatsink is also available as 1000mm (1m) variant.

Price for one sink: €57,00 (19% VAT included). Cutting this sink into 8 pieces of 125mm length would yield heatsinks of correct length costing €7,12 each.

[heinz1]

PSU Transformers. Let's make a list:

SumR (Canada)
(part number: RC0600 915 5; see post #179 and confirmed in post #181)

qusp

Toroidy (Europe)

samoloko, mravinsky, heinz1

CeeVee intends also to buy from Toroidy (or has them already). I will send a PM to CeeVee.

I have never ordered from Toroidy before. It would be great, if a previous buyer could contact them and ask for an offer.

Antek (USA)

alazira

to be seen whether there is enough interest

Here is the transformer specification.

This specification defines a 500VA transformer with enameled leads. We (the European buyers) have to decide whether we go for a 600 VA transformer (as with the SumR transformers) or whether we prefer flexible leads. (For discussion see here).