Ace's softly upgraded: 1969 double output capacitor improvement
When it comes to jlh1969 small a, burners always think of its warm and loose medium frequency — but the classic single-out-capacitation design occasionally shows short panels under low-frequency dynamics or high volume. The recent attempt to change the traditional single-capable output to a double-capable symmetry output has surprised the sound upgrade。
Traditional monolithic “mind regret”
The original 1969 (e. G., plate a in the chart) uses single-volume electroly decomposition (usually 3,300 mf) to isolate straight currents, while satisfying the basic hearing sense, the “polar properties” of the electroly decomposition caps allow small internal resistance differences at the time of the passing of positive and negative half-week signals, especially at low-frequency large motion, where asymmetrical discharges can lead to low-frequency softness and horizontal blurs; at the same time, leaks in the single caps can affect the stability of the static midpoint。
Double-carbed-up ideas
The core of the improved version (b plate) consists of two combinations of capacity electrolytic + symmetrical resistance: the single capping of the output end is split into two (usually 2,200-4700 mf) symmetrical caps, and is combined at both ends of the capacitation and eight times a resistance。
The great thing about this design is:
Signal symmetrical transmission: a positive or negative half-weekly signal is transmitted independently through each of the two capacitors, eliminating the "polar internal resistance" of the single cape, with a more full low frequency dynamic and a marked increase in the depth of the dive
2. More stable static voltage: a sub-voltage network formed by a combination of electrical resistance that offsets the interference of the leak to the mid-point voltage and the opening of the engine is also less than a single-capable version
3. Irresistence: even if one of the units declines, the other will sustain the basic output and be more durable than the single capacitation programme。
Change in actual hearing
The most intuitive experience with a pair of four bookcases is the change of low frequency from "soft" to "flexible" — for example, when the drum poems are played, the drums go down and beam faster; the medium frequency has a slight increase in human sound density and has softer control; and the high frequency, although it has not changed in a subversive way, is more natural than a single version of the contour。
It is important to note that double capacitor needs to choose the same brand, the same batch of electrolytic capacitors (e. G., the roe gold bullet or the ina brown god), otherwise the subtle differences in capacity or internal resistance will have an impact。
Core component parameters (comparable to b panel circuit)
1. Output double capacitor
- specifications: 2200 μf/50v or 4700 μf/50v (recommends the same batch as brand, e. G. Ina rbd series, nicon kw series)
Number: 2
2. Capacitive and connected resistance
- specification: 8/2w metallic membrane resistance (accuracy > 1%)
Number: 2
3. Other key components (with original generic components)
- power tubes: c5200 (npn) + d669 (pnp) tubes (recommends a magnification multiplier of beta, 5% error)
- propulsion tube: a733 (pnp small signal tube)
- resisting type:
- r1 (replacement adjustment): 100 rounds of multi-hubs
- r2:47 (or 51)/1w fixed resistance
- input fractional pressure/replacement resistance: 100 k, 8. 2 k, 2. 7 k/0. 25 w membrane resistance
- capacitive type:
- enter compatible capacitor: 0. 5-1 μf (recommended to use wima mkp film)
- resilient/sidecarrying: 104 (0. 1 μf) china, 100 μf/50v electrolytic, 220 μf/50v electrolytic
Fit load (horn)
- support for four or eight anti-horns and, if you use four speakers, recommend 4,700 mf to ensure low frequency dynamics。
