Ladyday Signature amplifier

The Ladyday Signature rises to new heights.

Output transformers:
Used in some extreme high end amplifiers, these are wound with a 'perfect lay' technique using paper and transformer cores from Japan. 'Perfect lay' winding allows for tighter packing of layers and less interwinding capacitance so that a larger core can be used without sacrificing the high frequencies. The larger core is desirable to prevent saturation of the signal at high power levels and during transients. Bass plays deeper and at full rated power.
Multiple (5) taps on the secondary provide adjustable primary impedance from 2K to 8K so the following power tubes can be used: VT52/10Y/205D/45/50/PX4 /PX25/2A3/300B.

4/8/16ohm speaker taps: Nominal impedance ratings are often misleading. An 8 ohm rated speaker may be 6 or 12 ohms and often sounds better on 4 or 16 ohm taps. Always try different taps to determine which gives best sound. When the right tap is selected, soundstage will be bigger and sounds more energetic. Also 16 ohm taps allow using vintage high efficiency speakers. Connecting them to 8 ohms is a compromise.

The power transformer comes with all the voltage taps necessary for the advanced DIY'r to use all the above mentioned tubes: 2.5V/5V/7.5V-3A power tube filament taps.
400/300/ B+ supply and 2 x 25V buck/boost windings to get the desired B+.
5V/4A taps for rectifier, 6.3V and 10V - 1A for the input/driver tube heater supply. In addition, the Tentlabs filament supplies can also be accommodated. Driver tubes can be 6SL7, 6SN7, WE310A, 6H30, 6C45pi, 417 etc.
The power transformer core material is the highest grade - H14 from Japan. Why is the core so important in a power transformer? Higher grade = less saturation = fewer windings needed = lower impedance = less power supply sag during transients and faster recovery.

The new chassis is non-magnetic with a copper ground plane. It is deeper giving more room for our beloved oil caps and big chokes if desired. Non-magnetic: ever breadboard a circuit - sounds great, but stick it in a steel chassis and the magic is gone? The LD Sig non-metallic chassis removes the magnetic interference effects of a steel chassis in the audio band.

30 Watt wirewound adjustable cathode resistor for the power tube is standard as is the choke for power supply and genuine Nichicon power supply caps. Copper ground plane standard. So... the sky's the limit here. The LD Signature allows many possibilities to explore popular SET configurations such as WE91, MU, SRPP etc.

With careful orientation and layout, the LD continues to set the standard - 0.55mv output rimple with simple SRPP and diode bridge feeding the filaments of the power tube. this drops to 0.45mv with the CCS parallel 6SL7 driver and even lower with the Tentlabs filament supply. Something about having your cake and eating....

The LD Signature is improved in every way and offers even more flexibility as an experimenter's platform.

Prices are a little higher but there has been a major increase in quality. There is no getting around higher costs for parts and (transformer)iron and all manufacturers face the same choices. Beware the proliferation of tube amps which cut corners in the areas you can't see, with fake caps, re-sleeved caps, scrap iron cores and low purity copper -all common practices-, and sell for unbelievably low prices.




Specifications: (may change without notice)

• Power output, 300B: 7-9W x 2 RMS @ 1KHZ Class A depending on circuit
• Frequency response: 12Hz to 47KHz (-3 dB@5W) (20hz to 20k -0.5db)
• THD: <1% (5W@1KHz)
• Signal to noise: 90dB or better (0.55mv at the speaker outputs)
• Input sensitivity and impedance: 1.5V, 100K (310A driver is .5v)
• Power: 110/120/220/230/240V AC +- 10%, 50Wx2
• Dimension (mm): 412(L) x 230(W) x 75/210(H) (not including/including transformer)
• Weight: 16Kg per chassis = 32Kg
• Shipping Weight: 17Kg per chassis
• Standard Tubes (priced separately): 300Bx2, 6N9PJ(6SL7)x2, 5Z3PAx2 or 274b, 310A, 300B
• NEW: Power transformer is low output impedance EI type, custom made with imported cores.
• Output transformer is larger imported core and 'perfect lay' windings.
• Speaker outputs: 0/4/8/16ohms
• non-magnetic chassis