Saturday, November 28, 2015

BCP-15 + plate chokes.

These are a special version of our standard BCP-15's. 

Same electrical specs. It's a plate choke optimized for the 45 tube. Standardly airgapped for 40 mils of plate current. It has 50 henries of inductance and 525 (nominal) ohms of winding resistance. 

An alternate airgap can be used which yields 40 henries at 50 mils of plate current. This arrangement can be used with 2A3 tube operating at 300 volts on the plate, -45 grid volts, and 50 mils of plate current.

What makes these special is that the plus model depicted in the photo incorporates key elements of our new proprietary inductor designs as highlighted in a post earlier this month.

It has mirror-imaged twin coils in a series-aiding noise cancelling (humbucking) arrangement. It is stacked with premium M3 laminations (.009" thick) which have exceptionally low core losses. Comes in solid brass channel frames. All solder connections are made with a silver bearing alloy.

Available in limited quantities for a limited period of time. These are the best BCP-15's hat I have made. 

$250 a pair plus shipping. Email me at to order.

Thursday, November 05, 2015

Introduction of a UHP series of inductors/transformers

Hello Folks,

I'm really happy to announce a premium series of mirror-imaged twin coil, noise cancelling, and symmetric low capacitance designs. These will be available as an option in many of our plate chokes, grid chokes, input transformers, etc.

These ultra high performance designs have been carefully engineered and evaluated over a lengthy development time-frame. We have gained enough experience in building these to be able to offer them as enhancements to our already heralded audio inductors and transformers. These are much more labor intensive to build and hence the pricing will reflect the increased costs.

These UHP designs are strictly proprietary, and are exclusive to MagneQuest. I will not provide in-depth technical treatises on our proprietary developments. Where possible I will endeavor to spell out what the performance advantages are in specific applications.

Many of the major concepts incorporated into this new series have been demonstrated in prior OEM work that we've done for Wavelength Audio as well as some of the craft techniques developed for use in our very special Mexico series B7 input transformers. We recently built some OEM power supply filter chokes for Serious Audio (to their electrical specs) that embody several of the key concepts described above.

Our first offerings will be for our B7 10K:10k input transformers. All electrical specs such as impedances and power levels remain as previously published.

We have some top shelf Penny & Giles RF-15 potentiometers avaiable for purchasers of our input transformer listed above.

Next up will be some of our plate chokes\grid chokes.


Friday, October 30, 2015

A New Attenuator

there's a new attenuator available. Read DHTRob's impressions below.
the unit reviewed was a 100K ohms... and I actually have some inductor loading options for this high value...
but in all likelihood Amtrans can probably make a 10K version in which case you can use our B7 10K:10K input trans with the 10K attenuator across the secondary.
Also... here's a sneak preview... I will soon be announcing a new series of "mirror-imaged, twin coil, hum-bucking, and symmetric low C" designs.... which will be available as an option in many of our plate chokes, grid chokes, input transformers, etc....

Saturday, March 07, 2015

We love to hear from you

Questions, comments, and order inquiries can be communicated to us via several different  SMS, chat, and messenger apps.

Via KIK:

Download Kik by going to on your phone (it's free and crazy fast). My Kik username is "mqracing" - add me!

Via Whatsapp: please contact me first by email

Via BBM: please contact me first by email 

Via Facebook: please contact me first by email 

My email is 

Tuesday, February 03, 2015

DIY Plans: HTS-5504-1

Hello folks:

We've had a lot of inquiries on the MQR-5504 power transformer which was used in the Baby O and Bugle circuits designed by Gordon Rankin of Wavelength Audio fame.

Since we are a really small (nano sized :=) winding house and are frequently booked pretty solid--- we aren't able to accomadate building this power transformer in-house any longer. It's just not efficient for us to produce these.

Enter Heyboer transformers. I contacted them and asked if they would have an interest in building these for our customers. I've supplied them with the original blueprints so that they could make an electrical equivalent. 

The new part # for units sourced through Heyboer is HTS-5504-1. You can and must order direct from Heyboer. Units produced by Heyboer will be covered by their warranty if any.

They will have a spec sheet available for this part number.

Pricing as relayed to me will be $130 for singles and $110 each if ordered in pairs.

ALL questions and queries should be directed to Heyboer. 

phone: 616-842-5830 or email at