Value for money transformers - Zorro

Proudly presenting... 

Value for money power transformers - Zorro Transformers

In this turbulent times, where times are bad, jobs are scarce, pay increment is puny, bonus is shaky, funds for leisure or pleasure will be eliminated or reduced significantly. We totally understand, and therefore, we introduce this super value for money transformers for the sake of all the DIYers out there.

These will be considered as our Level 0 products. They are better than your run of the mill, of the shelf transformers with those shiny low grade cores. Of course, they still cannot compete with our Level 1 and above transformers. Still, they are made with very decent materials and can be considered as audio grade transformers.

Zorro Power Transformers

• 100W EI H50 0.5mm U$39
• 100W EI H14 0.35mm U$45
• ~2.3KG

• 150W EI H14 0.35mm U$53
• 180W EI H14 0.35mm U$66
• 220W EI H14 0.35mm U$73
• ~ 3.9KG

• 130W EI H50 0.5mm U$47
• 150W EI H50 0.5mm U$50
• 150W EI H14 0.35mm U$60
• ~3.3KG

• 266W EI H50 0.5mm U$80
• 280W EI H50 0.5mm U$85
• 350W EI H50 0.5mm U$105
• 350W EI H14 0.35mm U$111
• 380W EI H14 0.35mm U$124
• ~6KG

Features

- DuPont high temp bobbin
- 0.75mm copper foil electrostatic shield / ground
- Single or dual primaries allowed
- Secondaries - 4 sets only, 5 sets (depends on complexity) for higher power version 
- Higher power / higher voltage - please email us  
- Add at least 15-20% of VA reserve to cater for losses and lower temp operation 

Transformer Ordering Notes, due to power factor considerations:

• For high voltage B+
• Apply at least 1.5x (150%) of intended load
• 2x is recommended for high fever audiophile use
• Say 200mA DC is required, assume 300mA minimum when multiplying with the AC voltage for VA calculation.

• For low voltage DC filament supply
• Apply at least 2x (200%) of intended load
• 3x is recommended for high fever audiophile use
• Say 3A DC is required, assume 6A minimum when multiplying with the AC voltage for VA calculation.

Zorro Baby Power Transformers:

• 85W EI H50 0.5mm (black, better than white type) U$34
• 85W EI H14 0.5mm (black, better than white type) U$39

Features 
- End bells, about 1.75KG
- Unloaded voltage may be higher
- Electrical specs are as follow (fixed specs): 

Type1:
Pri:
- 0-220-230V
Sec:
- 0-230-250V 0.15A
- 0-5V-6.3V 2A
- 6.3V 2A
- 6.3V 2A

Type2
Pri:
- 0-220-230V
Sec:
- 180V-0-180V 80mA
- 6.3V 5A
- 3.15V-0-3.15V 4A

Type3
Pri:
- 0-220-230V
Sec:
- 180V-0-180V 80mA
- 6.3V 5A
- 6.3V-0-6.3V 2A

B+ Zorro Chokes (H50/H14)

• 10H 0.2A U$20
• 10H 0.5A U$44
• 10H 0.25A U$28
• 5H 0.2A U$21
• 5H 0.3A U$28
• 15H 0.2A U$28
• 5H 0.25A U$24

Zorro Transformers Purchasing Tips:

• Purchase more units to lower down the shipping charges
• Economical express shipping for Singapore, Malaysia, Hong Kong and China
• EMS for all other countries - fast, safe and efficient, slightly pricey but worth it
• Items will be shipped from Shenzhen, China warehouse
• Payment - pay for transformer costs first, and then pay actual shipping when orders are ready to ship.

 

History 

In order to lower the cost of Zorro transformers to such level, we have to move the Zorro transformer manufacturing to China, subcontract it to a big transformer factory to mass produce it for us in batches. In order to maintain the quality, we do not simply use any factory but one with the technical capability and quality.

• Experienced contract manufacturer transformers used in home, telecommunications, mechanical, industrial electronics and electrical appliances. 
• Manufactured by technicians with over >10 years of experience
• Manufactured using automatic winding machine, with high torque automatic alignment machine and automatic lamination insertion machine
• Equipped with various electrical measurement equipment to ensure product meeting specifications and quality
• Equipped with vacuum impregnation machine and automatic controlled temperature oven for baking transformers
• Stocked various high temp bobbin and various casing for EI41 to EI133 sizes, with H50, H14, Z11 and various other transformers cores. 
• Guaranteed pure copper magnetic wires are used. All comes with 1 year warranty.

Enjoy!

J&K Audio Design
1/26/2017

Power Transformer Price List

Level  2 & level 3 Power Transformer Price List

• EI power transformers - Z0 and Z11 cores (level 2)
• "SHiB" - Super Hi-B Double C core (level 3) 
• Level 0 and level 1 - please email

Features

• Multiple electrostatic shields
• Using the best quality materials - imported OFC wires, insulation, bobbin, and etc
• Multiple mains possible 100Vac - 240Vac
• Balanced / bi-filial winding for center-tapped taps (not for ultra high voltage)
• Regulation ~5%, low temperature, low noise, high efficiency design 
• Secondary taps - user defined (up to 6 sets, depending on core size) 
• Power transformers - can be configured and used as isolation transformers
• Designed for 24/7 operation 
• Other sizes / VA - please email us for availability or customization
• Potting - standard colors only. Other colors with extra charge - ask us for details

Level 1 Power Transformer Price List (unlisted - POA) 

• EI Z11 (0.35mm 35JG155), EI Z10 (0.27mm 27JG120, 27JG130), EI Z9 (0.23mm 23JGSD085(laser stripe), 23JGH095) 
• Better accuracy and quality than Level 0
• Potting available at extra charge - depends on size (up to EI 114) - potted with high grade potting compound (high strength, high temp, corrosion resistant, high insulation strength, high heat dissipation), with nickel plated copper turrets 
• Dupont Nomex T410 teflon film for high voltage transformers

Level 0 Power Transformer Price List

• H15 0.35mm lamination 
• Best bang or the buck 
• Machine wind, high temperature bobbin, vacuum impregnation, oven backed 
• Hipot tested and outputs verified

General notes / tips

• Users should keep 10-20% VA unused from total core VA for lower operating temperature and stability - 75% will be ideal. 
• Higher number of secondary taps will lower efficiency.
• Mixture of high and low voltage, or high and low current will lower efficiency.
• Please provide clear schematic if you are unsure of what to order.
• Separate the B+ transformers and DC filament transformers into 2 transformers for lowest noise. High current bridge or solid state diodes for DC rectification generates A LOT of noise.

J&K Audio Design
6/12/2016

2 coil choke

What is a 2-coil choke? It is a choke with 2 windings wound onto the same iron core. The advantage of 2-coil choke is that it can be configured in different ways, according to the user desired effects! 

Above is how a 2-coil choke symbol looks like. It is having 2 coils wound on the same iron core, as shown in the above picture.

There are four ways of connection that I can think of right now for tube amplifier power supply usage. 

1. Series mode
2. Parallel mode
3. Common mode noise rejection
4. Differential mode noise rejection

Let's take a 10H 100mA 50 Ohm DCR choke as example:

Mode 1 - 10H with 100mA capacity and 50 Ohm DCR

Mode 2 - 2.5H with 200mA capacity and 25 Ohm DCR

Mode 3 - mH in inductance, 100mA, usually use in AC circuit only

Mode 4 - 10H with 100mA capacity and 50 Ohm DCR

Such 2-coil power supply chokes are made to couple well at low frequency, usually at double the mains line frequency of 50/60 Hz (results of full-wave/bridge rectification). Mutual coupling between the coils will be low at higher frequencies, and will act as 2 different chokes at higher frequencies. This behavior can be used in advantage to different applications.

What are differential mode noise and common mod noises? I think you guys can find that out using Google. There is no need for me to reinvent the wheel again over here. 

Mode 3 will reject common mode noise and mode 4 will reject differential mode noise, simple as that. You can treat them like a differential mode choke (DMC) and common mode choke (CMC) commonly used in power supplies. The only difference here is that the standard CMC or DMC do not pass DC where it works in the AC region before rectification process. For our DC chokes here, it works with DC in mind.

Common Mode Choke

Differential Mode Choke

Do note that for connection #3 - common mode noise rejection configuration, it is usually used in AC circuit mostly. You can apply this in DC circuit too but it does not act as a power supply choke anymore in such configuration. That is, it is no longer a capacitor-input filter in the above diagram. You will need to add another choke to provide the usual filtering function to complement the "common mode choke".

Using such 2-coil chokes will be beneficial to gain extra edge on getting a quieter power supply for your amplifiers. Do not forget this when you are designing your next amplifier. An example of application would be as follow:

• 3 stages: rectifier -> 2-coil choke in series or parallel mode -> 2-coil choke in common mode config -> 2-coil choke in differential mode config. 
• 2 stages: rectifier -> 2-coil choke in differential mode config -> 2-coil choke in common mode config 
• And many more!

Now, go order a 2-coil choke and replace all the chokes in your amplifier to lower the noise floor and improve the sound!

4/15/2015

J&K Audio Design

Product Lists  
Level 0

Level 1: link 1, link 2, link 3

Level 2: link 1, link 2, link 3, link 4, link 5, link 6 

Level 3: depends on type, size and complexity. Email us for details.

Iso-trans: link 1, link 2

* Finished amplifiers, DACs, audio gadgets, upgrades and repairs - this is not our core business and we do it out of passion. We do not have fixed models, fixed price and we customize for each individuals. The sky is limit of creativity.  

* Our product lines are always improving and increasing. If you do not see what you want, contact us!  

* Please email for volume discounts, distributor and OEM pricing.

Low Cost Tube Preamp

Today's topic is about low cost tube preamp.

Everything is about money, money and money nowadays. With the ever rising living cost, coupled with poor money management of you know who, added with GST, it is harder and harder to survive nowadays.

What can we do if we still want high performance with little money involved? Well, you've got what you ask for today! When people talks about tube preamp, the first thing that associates that with high quality is tube preamp with output transformer, WOT Preamp as some call it. 

Wait a minute. Output transformers are expensive, aren't they? Tube preamp or linestage output transformer are expensive too, right? Especially the high performance ones! Well, you are right! Or, you were right, till we offered the ALOS series of output transformers.

I believe this has slipped some of our follower's eyes. It's alright. We are re-introducing this baby here again. It is being disguised as Head-Phone output transformer, that's why it slipped most eyes that wanted a tube preamp output transformer. Take a look below! 

ALOS Output Transformer link

ALOS-75HP

Power: 2W(20Hz) Single Ended Bandwidth: * Pentode: 20-65kHz -3dB * Triode: 10-60kHz -2dB Primary: 7.5K; Secondary: 0-150-300 Ohm Core: 35H360 (H14) EI66 Pri. DCR: 506 Ohm(B-P) Sec. DCR: 38 Ohm (0-300 Ohm) Primary Inductance: 50H(40Hz, 5Vrms) Primary Current: 40mA (50mA max) * Matched in actual operating conditions. * DCR <1%, Primary Inductance <5%.

U$99/pr

Yes, you got it right! It is only U$99/pr. Of course, with such price, you can't expect too much out of it too, but the specifications are very decent, and decent enough to be used in not just low cost tube preamp where it can be considered as high performance tube preamp where the preamp output transformer actually boasts of 10Hz - 60KHz @ -2dB frequency response in Triode mode. 

Tell me, how many speakers actually can reproduce such frequency response? Very few. And for those who owns these speakers, they don't mind paying for our higher end output transformers with better specs anyway. 

This low cost tube preamp output transformer has a highish primary impedance of 7.5K with a handsome primary inductance of 50H. It comes with primary current of 40mA too. That is good enough for most of the preamp tubes out there, or even small power tubes. If you use tubes with low Rp (plate impedance), you can actually widen the already quite decent bandwidth. 

The secondary comes with 2 taps, and is configurable to single ended output or balanced output. The 150 Ohm tap is the center-tap, the 0 Ohm and 300 Ohm taps are the +/- taps. Now this gets even better, right? It is now a low cost high performance balanced tube preamp with output transformer! I bet a lot of the commercial can't even come close to your design if you do it right. 

The output impedance can be configured to 150 Ohm or 300 Ohm, which is low enough for most power amplifiers, even solid state versions. What about the gain of this tube preamp output transformer? x = gain.

• Z2/Z1 = x²

For 300 Ohm output, x = SQRT of (7500/300) = 5 (5:1 step down)
For 150 Ohm output, x = SQRT of (7500/150) =7 (7:1 step down)

If you power amplifier needs 2Vrms for full power, then anything tube with a gain of 7 or more will be sufficient for this low cost tube preamp. I can already think of many in my mind - 5687, 5842, 6C45, EL84, EL83, 6DJ8, 6922, 7119, E88CC, EC88, C3M, C3G, and many, many more...

With the low pricing of ALOS-75HP, one can even buy 4 units and make it a true 4 channel preamp! They can drive 2 monoblock power amplifiers and 2 subwoofers, or 4 monoblock power amplifiers for bi-amping! Fun right?

So, why wait, go ahead and order 4 units from us for your low cost high performance tube preamp project! 

P/S: do not forget that this can be used as headphone output transformer too!  

J&K Audio Design
4/14/2015

Product Lists  
Level 0

Level 1: link 1, link 2, link 3

Level 2: link 1, link 2, link 3, link 4, link 5, link 6 

Level 3: depends on type, size and complexity. Email us for details.

Iso-trans: link 1, link 2

* Finished amplifiers, DACs, audio gadgets, upgrades and repairs - this is not our core business and we do it out of passion. We do not have fixed models, fixed price and we customize for each individuals. The sky is limit of creativity.  

* Our product lines are always improving and increasing. If you do not see what you want, contact us!  

* Please email for volume discounts, distributor and OEM pricing.

Output Transformers - AL0S

ALOS = Advance Level O(0) Series Output Transformers
* Improved Performance of Level 0 transformers.
* High cost / performance ratio.
* Standardization for affordability.
* Open frame with solder tags only.
* No customizations entertained.
* H14 EI core for lowering cost.

Model	Specifications	Price
ALOS-55SE	Power: 5W(20Hz) Single Ended Bandwidth: 20-40KHz -3dB Primary: 5.5K, Secondary: 0-4-8 Ohm Core: 35H360(H14) EI66 DCR: 424 Ohm(B-P) Primary Inductance: 35H(40Hz, 5Vrms) Primary Current: 60mA max * Matched at actual operating condition! * DCR <1 data-blogger-escaped-br="" data-blogger-escaped-inductance="" data-blogger-escaped-primary="">	U$89/pr
ALOS-35SE	Power: 10W(20Hz) Single Ended Bandwidth: * Pentode: 20-60kHz(-3dB) * Triode: 10-75kHz(-2dB) Primary: 3.5K, Secondary: 0-4-8 Ohm Core: 35H360 (H14) EI76 DCR: 215 Ohm(B-P); 1.05 Ohm(0-8 Ohm) Primary Inductance: 28H(40Hz, 5Vrms) Primary Current: 60mA (75mA max) * Matched at actual operating condition. * DCR <1 data-blogger-escaped-br="" data-blogger-escaped-inductance="" data-blogger-escaped-primary="">	U$149/pr
ALOS-10KPP	Power: 16W(30Hz) Push Pull Bandwidth: 10-60kHz -2dB Primary: 10K; Secondary: 0-4-8 Ohm Core: 35H360 (H14) EI76 Pri. DCR: 312 Ohm(P-P) Sec. DCR: 0.51 Ohm (0-8 Ohm) Primary Inductance: 86H(40Hz, 5Vrms) * Matched in actual operating condition! * DCR <1 data-blogger-escaped-br="" data-blogger-escaped-inductance="" data-blogger-escaped-primary="">	U$109/pr
ALOS-75HP	Power: 2W(20Hz) Single Ended Bandwidth: * Pentode: 20-65kHz -3dB * Triode: 10-60kHz -2dB Primary: 7.5K; Secondary: 0-150-300 Ohm Core: 35H360 (H14) EI66 Pri. DCR: 506 Ohm(B-P) Sec. DCR: 38 Ohm (0-300 Ohm) Primary Inductance: 50H(40Hz, 5Vrms) Primary Current: 40mA (50mA max) * Matched in actual operating conditions. * DCR <1 data-blogger-escaped-br="" data-blogger-escaped-inductance="" data-blogger-escaped-primary="">	U$99/pr
ALOS-5PP	Power: 30W(30Hz) Push Pull Bandwidth: * Ultra Linear: 20-60kHz -0.5dB +cathode negative feedback * Ultra Linear: 20-50kHz -0.5dB * Standard: 20-25kHz -0.7dB * Full load test: 18W, UL, 20Hz -0.4dB to 20kHz -0.05dB Primary: 5.5K (P-P); Secondary: 0-4-8-16 Ohm Core: 35H360 (H14) EI76 Pri. DCR: 205 Ohm(P-P) Sec. DCR: 1.36 Ohm (0-16 Ohm) Primary Inductance: 50H(40Hz, 5Vrms) * Matched in actual operating conditions. * DCR <1 data-blogger-escaped-br="" data-blogger-escaped-inductance="" data-blogger-escaped-primary=""> * Transformer tap for cathode negative feedback.	U$159/pr

J&K Audio Design
20 May 2014

Product Lists  
Level 0

Level 1: link 1, link 2, link 3

Level 2: link 1, link 2, link 3, link 4, link 5, link 6 

Level 3: depends on type, size and complexity. Email us for details.

Iso-trans: link 1, link 2

* Finished amplifiers, DACs, audio gadgets, upgrades and repairs - this is not our core business and we do it out of passion. We do not have fixed models, fixed price and we customize for each individuals. The sky is limit of creativity.  

* Our product lines are always improving and increasing. If you do not see what you want, contact us!  

* Please email for volume discounts, distributor and OEM pricing.

Amorphous Choke

Special introduction - we have been shipping lots of amorphous C core chokes and got really good feedback on how much improvement they bring to our customers!

Prequel: 
What are the ways of upgrading your existing amplifier, other than playing with interconnects, speaker cables, platform isolation, and various other tweaks?

For DIY-ers, they would say - just change the components! That, to them, would bring more significant changes than playing with external factors. With the same amount of $$$ used on cables or other tweaks, DIY-ers can upgrade their amplifiers substantially, really substantially!

Nowadays, interconnects and power cords cost over USD$1K-5K easily. Imagine what can be done with the same amount of money! One can use all silver internal wiring, all Mundorf Silver/Gold capacitors, branded resistors, BlackGate capacitors, and any audiophile components one can possibly imagine. USD$5K can almost (very close) buy a pure silver output transformer already!

Changing capacitors, resistors, internal wiring, mechanical components and such are pretty common nowadays. Today, I'm going to introduce you another modifications that will bring substantial ROI to your amplifier:

AMORPHOUS CHOKE!

1. For amplifiers with only RC filter, add an amorphous choke!
• Produces lower voltage + current ripple, lesser heat (more efficient), lower partnering capacitance needed.
2. For amplifiers with normal choke, add an amorphous choke! 
• Better micro-dynamics, micro-details, better filtration, lower noise.
3. For amplifiers with DC filament supply, add an amorphous choke!
• Natural slow start, protect your tube filament for longer life.
• Others are same as above points #1 and #2.
4. For amplifiers with resistive load, add an amorphous plate/anode choke! 
• Higher efficiency - lower voltage drop.
• Better AC reactance (higher load, better linearity!
5. And many more! 

We have published only 1 size of DCAMC-M01 amorphous double C core choke but we can custom make other sizes too. Do let us know if you need other value chokes.

For USD$109 for an amorphous double C core choke, high ROI tweaks never come cheaper than this. Nowadays, even exotic capacitors can cost many times of such price. Now, start using more chokes in your amplifier design!

Some people talking about of amorphous chokes:

• DHTRob
• Jimmy Auw
• VT52 
• Tamura A-4006 

Amorphous Double C Core Choke (nickel steel alloy) – DCAMC-M01

This is made using 4 pieces of C-core per transformer, having 8 pieces altogether for a pair of high end amorphous double C core nickel steel alloy choke. The amorphous C core is very thin and extremely brittle. Please do not drop the transformer to prevent damage. Take precaution when installing the transformer.

• Available types: air-gapped choke (various sizes within core permit able values)
• Primary inductance: 8H
• Primary current: 300mA maximum
• Primary DCR: 70 Ohm
• Weight: 1.2KG per piece
• Size: 60mm x 75mm x 90mm

J&K Audio Design
3 MAY 2014

Product Lists  
Level 0

Level 1: link 1, link 2, link 3

Level 2: link 1, link 2, link 3, link 4, link 5, link 6 

Level 3: depends on type, size and complexity. Email us for details.

Iso-trans: link 1, link 2

* Finished amplifiers, DACs, audio gadgets, upgrades and repairs - this is not our core business and we do it out of passion. We do not have fixed models, fixed price and we customize for each individuals. The sky is limit of creativity.  

* Our product lines are always improving and increasing. If you do not see what you want, contact us!  

* Please email for volume discounts, distributor and OEM pricing.

Nickel Ferrite Amorphous Output Transformer

Since I have more time this week, let me share some pictures of the 2 sets of poison that had gone to their new homes. :)

• 1st pair - 2.5K:8R/16R for 2A3, using L01 (oversided) quad C core, luxury stuff! 
• 2nd pair - 3.0/3.5K: 8R/16R for 300B, using L01 quad C core, tasteful!
• Both nickel ferrite amorphous cores!

Depending on the packaging material, a layer of foam added to the binding posts to protect the pins.

Wrapped in foam, protected by another layer of foam before going into the 1st box.

1st box goes into the 2nd box, with lots of foam protection.

Output transformer - pair 1 - Singapore

Output transformer - pair 2 - Singapore again!

J&K Audio Design
26 APR 2014

Product Lists  
Level 0

Level 1: link 1, link 2, link 3

Level 2: link 1, link 2, link 3, link 4, link 5, link 6 

Level 3: depends on type, size and complexity. Email us for details.

Iso-trans: link 1, link 2

* Finished amplifiers, DACs, audio gadgets, upgrades and repairs - this is not our core business and we do it out of passion. We do not have fixed models, fixed price and we customize for each individuals. The sky is limit of creativity.  

* Our product lines are always improving and increasing. If you do not see what you want, contact us!  

* Please email for volume discounts, distributor and OEM pricing.